Iyzico wrapper class with example payment and callback page. Iyzico library used v2.0.43 version from this repository https://github.com/iyzico/iyzipay-php

callback_page.php

$iyzicoPayment = new IyzicoPayment(
    config_item('iyzicoApiKey'),
    config_item('iyzicoSecretKey'),
    config_item('iyzicoBaseUrl')
);

//This source used for 3DS payment callbackUrl here we control the posted fields for result
if ($_POST['status'] != IyzicoPayment::SUCCESS_RESULT) {
    die('Error! :::: Payment failed');
}

// if MDStatus equal to 1 everything is ok and we can complete the 3D payment
$iyzicoMDStatus = !empty($_POST['mdStatus']) ? $_POST['mdStatus'] : NULL;
if ($iyzicoMDStatus != IyzicoPayment::SUCCESS_MD_STATUS) {
    die('Error! :::: ' . $iyzicoPayment->getThreeDMDStatusMessage($iyzicoMDStatus));
}

$iyzicoPaymentId        = !empty($_POST['paymentId']) ? $_POST['paymentId'] : NULL;
$iyzicoConversationData = !empty($_POST['conversationData']) ? $_POST['conversationData'] : NULL;
$iyzicoConversationId   = !empty($_POST['conversationId']) ? $_POST['conversationId'] : NULL;

// ThreeDS payment second step if everything is ok it will response true otherwise false
if (!$iyzicoPayment->threeDSPayment($iyzicoPaymentId, $iyzicoConversationId, $iyzicoConversationData)) {
    echi 'Error! :::: ';
    print_r($iyzicoPayment->getErrors());
}

echo 'OK ;) ::: Congraduations you did it.';

config.php

<?php

$config['iyzicoApiKey']    = '[API_KEY]';
$config['iyzicoSecretKey'] = '[SECRET_KEY]';
$config['iyzicoBaseUrl']   = 'https://api.iyzipay.com';

IyzicoPayment.php

<?php

namespace App\Classes\Iyzico;

use Iyzipay;
use Iyzipay\Model;
use Iyzipay\Options;
use Iyzipay\Request;

/**
 * Class IyzicoPayment
 * @author  Siavash Habil <amirkhiz@gmail.com>
 * @package App\IyzicoPayment
 */
class IyzicoPayment
{
    const SUCCESS_RESULT = 'success';
    const FAILED_RESULT  = 'failure';

    const SUCCESS_MD_STATUS = 1;

    /** Fraud Statuses */
    const FRAUD_CONFIRMED       = 1;
    const FRAUD_CONFIRM_WAITING = 0;
    const FRAUD_FAILED          = -1;

    /** Our commission for every basket item */
    const BASKET_ITEM_COMMISSION = 0.06;

    protected static $config;

    public    $htmlContent;
    protected $errors;

    /**
     * @var Model\SubMerchant
     */
    protected $subMerchant;

    public $cardToken;
    public $cardUserKey;
    public $installmentCount;
    public $fraudStatus;
    public $paymentId;
    public $paymentTransactionId;

    /**
     * @var Model\InstallmentInfo
     */
    protected $installment;
    protected $lang;

    /**
     * Discount value. This value calculate from pay price and will have the value of discount based on pay price
     * @var string
     */
    protected $discountValue;

    public function __construct($apiKey, $secretKey, $baseUrl)
    {
        self::$config = [
            'apiKey'    => $apiKey,
            'secretKey' => $secretKey,
            'baseUrl'   => $baseUrl,
        ];
    }

    public function apiTest()
    {
        $iyzipayResource = Model\ApiTest::retrieve(self::getConfig());

        debug_r($iyzipayResource);
    }

    protected static function getConfig()
    {
        $options = new Options();
        $options->setApiKey(self::$config['apiKey']);
        $options->setSecretKey(self::$config['secretKey']);
        $options->setBaseUrl(self::$config['baseUrl']);

        return $options;
    }

    /**
     * @param $subMerchantId
     *
     * @return bool
     */
    public function retrieveSubMerchant($subMerchantId)
    {
        if (empty($subMerchantId)) {
            $this->errors[] = 'Sub Merchant ID could not be empty!';

            return FALSE;
        }

        $request = new Request\RetrieveSubMerchantRequest();
        $request->setLocale(Model\Locale::TR);
        $request->setConversationId(time());
        $request->setSubMerchantExternalId($subMerchantId);
        $subMerchant = Model\SubMerchant::retrieve($request, self::getConfig());

        if ($result = $this->_getResult($subMerchant)) {
            $this->subMerchant = $this->_getSubMerchantFields($subMerchant);
        }

        return $result;
    }

    public function installments($price, $cardNumber = NULL)
    {
        $request = new Request\RetrieveInstallmentInfoRequest();
        $request->setLocale(Model\Locale::TR);
        $request->setConversationId(time());
        if (!empty($cardNumber)) {
            $request->setBinNumber(substr($cardNumber, 0, 6));
        }
        $request->setPrice($price);
        $installmentInfo = Model\InstallmentInfo::retrieve($request, self::getConfig());

        if ($result = $this->_getResult($installmentInfo)) {
            $this->installment = $this->_getInstallmentFields($installmentInfo);
        }

        return $result;
    }

    /**
     * @param $products
     * @param $paymentInfo
     * @param $cardInfo
     * @param $billingInfo
     * @param $callbackUrl
     * @param bool $subMerchantKey
     * @param bool $confirmProduct
     *
     * @return bool
     */
    public function payment($products, $paymentInfo, $cardInfo, $billingInfo, $callbackUrl, $subMerchantKey = FALSE, $confirmProduct = TRUE)
    {
        if (!isset($cardInfo['buying_policy'])) {
            $this->errors[] = sprintf(lang('form_validation_required'), lang('buying_policy'));

            return FALSE;
        }

        $this->installmentCount = (!empty($cardInfo['installment']) && !empty(intval($cardInfo['installment']))) ?
            intval($cardInfo['installment']) : 1;

        if (!empty($this->discountValue)) {
            $paymentInfo['paidPrice'] = $paymentInfo['paidPrice'] - $this->discountValue;
            if ($paymentInfo['paidPrice'] <= 0) return TRUE;
        }

        if ($this->installmentCount > 1) {
            if ($this->installments($paymentInfo['paidPrice'], preg_replace("/[^\d]*/", '', $cardInfo['card_number']))) {
                $installments = $this->getInstallment();
                foreach ($installments[0]['installmentPrices'] as $installment) {
                    if ($this->installmentCount == $installment['installmentNumber']) {
                        $paymentInfo['paidPrice'] = $installment['totalPrice'];
                    }
                }
            }
        }

        $paymentInfo['registerCard'] = (!empty($paymentInfo['registerCard']) && !empty(intval($paymentInfo['registerCard']))) ?
            intval($paymentInfo['registerCard']) : 0;

        //Create payment request
        $request = new Request\CreatePaymentRequest();
        $request->setLocale(Model\Locale::TR);
        $request->setConversationId(time());
        $request->setPrice($paymentInfo['price']);
        //$request->setPrice(1);
        $request->setPaidPrice($paymentInfo['paidPrice']);
        //$request->setPaidPrice(1);
        $request->setCurrency(Model\Currency::TL);
        $request->setInstallment($this->installmentCount);
        $request->setBasketId(time());
        $request->setPaymentChannel(Model\PaymentChannel::WEB);
        $request->setPaymentGroup(Model\PaymentGroup::PRODUCT);

        if (!empty($cardInfo['3d_payment'])) {
            $request->setCallbackUrl($callbackUrl);
        }

        //Set Card info
        $request->setPaymentCard($this->_setCardInfo($cardInfo, $paymentInfo['registerCard']));

        //Set Buyer information
        $request->setBuyer($this->_setBuyer($billingInfo));

        //Set Billing information
        $request->setBillingAddress($this->_setBillingInfo($billingInfo));

        //Set Products
        $request->setBasketItems($this->_setProducts($products, $subMerchantKey));
        //log_message('PAYMENT details ;::: ' . print_r($request, TRUE));

        //Make payment request
        if (!empty($cardInfo['3d_payment'])) {
            $payment           = Model\ThreedsInitialize::create($request, self::getConfig());
            $this->htmlContent = $payment->getHtmlContent();

            //Set this value to session to check after success payment
            $_SESSION['registerCard']   = $paymentInfo['registerCard'];
            $_SESSION['confirmProduct'] = $confirmProduct;
        } else {
            $payment = Model\Payment::create($request, self::getConfig());
        }

        //In 3DS payment after SMS confirmation we should save card and get payment items to approve payment
        //and this part just run when we do payment directly
        if ($payment->getStatus() == self::SUCCESS_RESULT && empty($cardInfo['3d_payment'])) {
            $this->fraudStatus = $payment->getFraudStatus();
            if ($this->fraudCheck($this->fraudStatus)) {
                $this->paymentId = $payment->getPaymentId();
                $this->directPaymentSuccessActions($payment, $paymentInfo['registerCard'], $this->fraudStatus, $confirmProduct);
            } else {
                $this->errors[] = lang('fraud_payment');

                return FALSE;
            }
        }

        return $this->_getResult($payment);
    }

    /**
     * @param Model\Payment $payment
     * @param int $registerCard
     * @param int $fraudStatus
     * @param bool $confirmProduct
     */
    protected function directPaymentSuccessActions(Model\Payment $payment, $registerCard, $fraudStatus, $confirmProduct = TRUE)
    {
        if ($fraudStatus == self::FRAUD_CONFIRMED) {
            if (!empty($registerCard)) {
                // Update user card key *******
                // if (empty($this->user['card_user_key'])) {
                // }

                $this->cardToken = $payment->getCardToken();
            }

            //TODO It should done with Thread
            foreach ($payment->getPaymentItems() as $paymentItem) {
                /** @var Model\PaymentItem $paymentItem */

                //TODO if we have more than one product for each selling we should change this algorithm
                $this->paymentTransactionId = $paymentItem->getPaymentTransactionId();

                if ($confirmProduct) {
                    $this->confirmProduct($paymentItem->getPaymentTransactionId());
                }
            }
        }
    }

    /**
     * @param Model\ThreedsPayment $payment
     * @param int $registerCard
     * @param bool $confirmProduct
     */
    protected function threeDSPaymentSuccessActions(Model\ThreedsPayment $payment, $registerCard, $confirmProduct = TRUE)
    {
        if (!empty($registerCard)) {
            // Update user card key *******
            // if (empty($this->user['card_user_key'])) {
            // }

            $this->cardToken = $payment->getCardToken();
        }

        //TODO It should done with MQ
        foreach ($payment->getPaymentItems() as $paymentItem) {
            /** @var Model\PaymentItem $paymentItem */

            //TODO if we have more than one product for each selling we should change this algorithm
            $this->paymentTransactionId = $paymentItem->getPaymentTransactionId();

            if ($confirmProduct) {
                $this->confirmProduct($paymentItem->getPaymentTransactionId());
            }
        }
    }

    /**
     * @param $paymentId
     * @param $conversationId
     * @param $conversationData
     *
     * @return bool
     */
    public function threeDSPayment($paymentId, $conversationId, $conversationData)
    {
        $request = new Request\CreateThreedsPaymentRequest();
        $request->setLocale(Model\Locale::TR);
        $request->setConversationId($conversationId);
        $request->setPaymentId($paymentId);
        $request->setConversationData($conversationData);
        $threeDSPayment = Model\ThreedsPayment::create($request, self::getConfig());

        if ($threeDSPayment->getStatus() == self::SUCCESS_RESULT) {
            $this->fraudStatus = $threeDSPayment->getFraudStatus();
            if ($this->fraudCheck($this->fraudStatus)) {
                $this->paymentId = $threeDSPayment->getPaymentId();
                $this->threeDSPaymentSuccessActions($threeDSPayment, $_SESSION['registerCard'], $_SESSION['confirmProduct']);
            } else {
                $this->errors[] = lang('fraud_payment');

                return FALSE;
            }
        }

        return $this->_getResult($threeDSPayment);
    }

    /**
     * @param $products
     * @param $paymentInfo
     * @param $cardInfo
     * @param $billingInfo
     * @param $callbackUrl
     * @param bool $subMerchantKey
     * @param bool $confirmProduct
     *
     * @return bool
     */
    public function paymentWithRegisteredCard($products, $paymentInfo, $cardInfo, $billingInfo, $callbackUrl, $subMerchantKey = FALSE, $confirmProduct = TRUE)
    {
        if (!isset($cardInfo['buying_policy'])) {
            $this->errors[] = sprintf(lang('form_validation_required'), lang('buying_policy'));

            return FALSE;
        }

        $this->installmentCount      = (!empty($cardInfo['installment']) && !empty(intval($cardInfo['installment']))) ?
            intval($cardInfo['installment']) : 1;
        $paymentInfo['registerCard'] = (!empty($paymentInfo['registerCard']) && !empty(intval($paymentInfo['registerCard']))) ?
            intval($paymentInfo['registerCard']) : 0;

        //Create payment request
        $request = new Request\CreatePaymentRequest();
        $request->setLocale(Model\Locale::TR);
        $request->setConversationId(time());
        $request->setPrice($paymentInfo['price']);
        //$request->setPrice(1);
        $request->setPaidPrice($paymentInfo['paidPrice']);
        //$request->setPaidPrice(1);
        $request->setCurrency(Model\Currency::TL);
        $request->setInstallment($this->installmentCount);
        $request->setBasketId(time());
        $request->setPaymentChannel(Model\PaymentChannel::WEB);
        $request->setPaymentGroup(Model\PaymentGroup::PRODUCT);

        if (!empty($cardInfo['3d_payment'])) {
            //TODO Test callback page for 3D payment
            $request->setCallbackUrl($callbackUrl);
        }

        //Set Card info
        $paymentCard = new Model\PaymentCard();
        $paymentCard->setCardUserKey($cardInfo['card_user_key']);
        $paymentCard->setCardToken($cardInfo['card_token']);
        $request->setPaymentCard($paymentCard);

        //Set Buyer information
        $request->setBuyer($this->_setBuyer($billingInfo));

        //Set Billing information
        $request->setBillingAddress($this->_setBillingInfo($billingInfo));

        //Set Products
        $request->setBasketItems($this->_setProducts($products, $subMerchantKey));

        //Make payment request
        if (!empty($cardInfo['3d_payment'])) {
            $payment           = Model\ThreedsInitialize::create($request, self::getConfig());
            $this->htmlContent = $payment->getHtmlContent();

            //Set this value to session to check after success payment
            $_SESSION['registerCard']   = $paymentInfo['registerCard'];
            $_SESSION['confirmProduct'] = $confirmProduct;
        } else {
            $payment = Model\Payment::create($request, self::getConfig());
        }

        //In 3DS payment after SMS confirmation we should save card and get payment items to approve payment
        //and this part just run when we do payment directly
        if ($payment->getStatus() == self::SUCCESS_RESULT && empty($cardInfo['3d_payment'])) {
            $this->fraudStatus = $payment->getFraudStatus();
            if ($this->fraudCheck($this->fraudStatus)) {
                $this->paymentId = $payment->getPaymentId();
                $this->directPaymentSuccessActions($payment, $paymentInfo['registerCard'], $this->fraudStatus, $confirmProduct);
            } else {
                $this->errors[] = lang('fraud_payment');

                return FALSE;
            }
        }

        return $this->_getResult($payment);
    }

    protected function _setProducts($products, $subMerchantKey)
    {
        $basketItems = array();
        foreach ($products as $product) {
            $basketItem = new Model\BasketItem();
            $basketItem->setId($product['product_id']);
            $basketItem->setName($product['product_name']);
            $basketItem->setCategory1($product['product_category']);
            // $basketItem->setCategory2($product['type']);
            $basketItem->setItemType(Model\BasketItemType::VIRTUAL);
            $basketItem->setPrice($product['product_price']);
            // $basketItem->setPrice(1);
            // $basketItem->setSubMerchantKey($subMerchantKey);
            // $basketItem->setSubMerchantPrice($this->_getBasketItemCommission($product['product_price']));
            // $basketItem->setSubMerchantPrice(1);
            $basketItems[] = $basketItem;
        }

        return $basketItems;
    }

    protected function _setBillingInfo($billingInfo)
    {
        $billingAddress = new Model\Address();
        $billingAddress->setContactName($billingInfo['name']);
        $billingAddress->setCity($billingInfo['city_label']);
        $billingAddress->setCountry($billingInfo['country_label']);
        $billingAddress->setAddress($billingInfo['address']);

        //$billingAddress->setZipCode($billingInfo['zipCode']);

        return $billingAddress;
    }

    protected function _setBuyer($billingInfo)
    {
        //TODO If below information is not filled in user information send warning to fill them
        $buyer = new Model\Buyer();
        $buyer->setId($billingInfo['id']);
        //TODO Get user first name and last name separately
        $buyer->setName($billingInfo['name']);
        $buyer->setSurname($billingInfo['sur_name']);
        $buyer->setGsmNumber($billingInfo['gsm_no']);
        $buyer->setEmail($billingInfo['email']);
        $buyer->setIdentityNumber($billingInfo['national_id']);
        $buyer->setLastLoginDate(date('Y-m-d H:i:s'));
        $buyer->setRegistrationDate(date('Y-m-d H:i:s'));
        //TODO Get user address in user settings page
        $buyer->setRegistrationAddress($billingInfo['address']);
        $buyer->setIp(getClientIp());
        $buyer->setCity($billingInfo['city_label']);
        $buyer->setCountry($billingInfo['country_label']);

        //$buyer->setZipCode("34732");

        return $buyer;
    }

    protected function _setCardInfo($cardInfo, $registerCard = 0)
    {
        $expDate   = explode('/', $cardInfo['expire_date']);
        $expMonth  = isset($expDate[0]) ? $expDate[0] : 00;
        $expYear   = isset($expDate[1]) ? $expDate[1] : 0000;
        $_cardInfo = array(
            'card_holder' => $cardInfo['card_full_name'],
            'card_number' => preg_replace("/[^\d]*/", '', $cardInfo['card_number']),
            'exp_month'   => $expMonth,
            'exp_year'    => $expYear,
            'cvv'         => $cardInfo['cvv'],
        );

        $paymentCard = new Model\PaymentCard();
        $paymentCard->setCardAlias($_cardInfo['card_holder']);
        $paymentCard->setCardHolderName($_cardInfo['card_holder']);
        $paymentCard->setCardNumber($_cardInfo['card_number']);
        $paymentCard->setExpireMonth($_cardInfo['exp_month']);
        $paymentCard->setExpireYear($_cardInfo['exp_year']);
        $paymentCard->setCvc($_cardInfo['cvv']);
        $paymentCard->setRegisterCard(intval($registerCard));

        if (!empty($registerCard)) {
            // Use card_user_key to register card in Iyzico
            $paymentCard->setCardUserKey($cardInfo['card_user_key']);
        }

        return $paymentCard;
    }

    /**
     * @return mixed
     */
    public function getErrors()
    {
        return $this->errors;
    }

    /**
     * @param Iyzipay\IyzipayResource $resource
     *
     * @return bool
     */
    protected function _getResult(Iyzipay\IyzipayResource $resource)
    {
        if ($resource->getStatus() == self::SUCCESS_RESULT) {
            return TRUE;
        } else {
            $debugBackTrace = array();
            foreach (debug_backtrace() as $item) {
                unset($item['object']);
                $debugBackTrace[] = $item;
            }
            $this->errors[$resource->getErrorCode()] = $resource->getErrorMessage();

            if ($resource->getErrorCode() == 5069) {
                $this->errors[$resource->getErrorCode()] = lang('for_pay_with_debit_card_should_use_three_d_payment');
            }

            return FALSE;
        }
    }

    /**
     * @return Model\SubMerchant
     */
    public function getSubMerchant()
    {
        return $this->subMerchant;
    }

    protected function _getSubMerchantFields(Model\SubMerchant $subMerchant)
    {
        if (!empty($subMerchant)) {
            $tempAddress = explode('/', $subMerchant->getAddress());
            $address     = isset($tempAddress[0]) ? trim($tempAddress[0]) : '';
            $district    = isset($tempAddress[1]) ? trim($tempAddress[1]) : '';
            $city        = isset($tempAddress[2]) ? trim($tempAddress[2]) : '';
            $country     = isset($tempAddress[3]) ? trim($tempAddress[3]) : '';

            return array(
                'name'           => $subMerchant->getName(),
                'email'          => $subMerchant->getEmail(),
                'first_name'     => $subMerchant->getContactName(),
                'last_name'      => $subMerchant->getContactSurname(),
                'company_name'   => $subMerchant->getLegalCompanyTitle(),
                'tax_office'     => $subMerchant->getTaxOffice(),
                'tax_no'         => $subMerchant->getTaxNumber(),
                'address'        => $address,
                'district'       => $district,
                'city'           => $city,
                'country'        => $country,
                'gsm'            => $subMerchant->getGsmNumber(),
                'national_id'    => $subMerchant->getIdentityNumber(),
                'iban'           => $subMerchant->getIban(),
                'type'           => $subMerchant->getSubMerchantType(),
                'subMerchantKey' => $subMerchant->getSubMerchantKey(),
            );
        }

        return FALSE;
    }

    /**
     * @return Model\InstallmentInfo
     */
    public function getInstallment()
    {
        return $this->installment;
    }

    /**
     * @param Model\InstallmentInfo $installmentInfo
     *
     * @return array|bool
     */
    protected function _getInstallmentFields(Model\InstallmentInfo $installmentInfo)
    {
        if (!empty($installmentInfo)) {
            $details = array();
            foreach ($installmentInfo->getInstallmentDetails() as $installmentDetail) {
                /** @var Model\InstallmentDetail $installmentDetail */

                $prices = array();
                foreach ($installmentDetail->getInstallmentPrices() as $installmentPrice) {
                    /** @var Model\InstallmentPrice $installmentPrice */

                    $prices[] = array(
                        'installmentPrice'  => $installmentPrice->getInstallmentPrice(),
                        'totalPrice'        => $installmentPrice->getTotalPrice(),
                        'installmentNumber' => $installmentPrice->getInstallmentNumber(),
                    );
                }

                $details[] = array(
                    'binNumber'         => $installmentDetail->getBinNumber(),
                    'price'             => $installmentDetail->getPrice(),
                    'cardType'          => $installmentDetail->getCardType(),
                    'cardAssociation'   => $installmentDetail->getCardAssociation(),
                    'cardFamilyName'    => $installmentDetail->getCardFamilyName(),
                    'force3ds'          => $installmentDetail->getForce3ds(),
                    'bankCode'          => $installmentDetail->getBankCode(),
                    'bankName'          => $installmentDetail->getBankName(),
                    'forceCvc'          => $installmentDetail->getForceCvc(),
                    'installmentPrices' => $prices,
                );
            }

            return $details;
        }

        return FALSE;
    }

    public function getThreeDMDStatusMessage($mdStatus)
    {
        switch ($mdStatus) {
            case 0:
                return lang('three_d_invalid_signature');
            case 2:
                return lang('three_d_not_registered_card_owner');
            case 3:
                return lang('three_d_not_registered_bank');
            case 4:
                return lang('three_d_not_registered_card_owner');
            case 5:
                return lang('three_d_not_verified');
            case 6:
                return lang('three_d_error');
            case 7:
                return lang('three_d_system_error');
            case 8:
                return lang('three_d_undefined_card_no');
        }

        return lang('error_code_not_found');
    }

    /**
     * @param $cardUserKey
     *
     * @return array|bool
     */
    public function retrieveUserCards($cardUserKey)
    {
        if (empty($cardUserKey)) {
            $this->errors[] = 'Card user key is required.';

            return FALSE;
        }

        $request = new Request\RetrieveCardListRequest();
        $request->setLocale(Model\Locale::TR);
        $request->setConversationId(time());
        $request->setCardUserKey($cardUserKey);
        $cardList = Model\CardList::retrieve($request, self::getConfig());

        //TODO Should set response to class public property

        if ($this->_getResult($cardList)) {
            return $cardList->getCardDetails();
        }

        return FALSE;
    }

    public function createCard($cardInfo)
    {
        $request = new Request\CreateCardRequest();
        $request->setLocale(Model\Locale::TR);
        $request->setConversationId(time());
        $request->setEmail($cardInfo['email']);
        $request->setExternalId($cardInfo['id']);

        $cardInformation = new Model\CardInformation();
        $cardInformation->setCardAlias($cardInfo['name']);
        $cardInformation->setCardHolderName($cardInfo['card_holder']);
        $cardInformation->setCardNumber($cardInfo['card_number']);
        $cardInformation->setExpireMonth($cardInfo['exp_month']);
        $cardInformation->setExpireYear($cardInfo['exp_year']);
        $request->setCard($cardInformation);

        $card = Model\Card::create($request, self::getConfig());

        if ($result = $this->_getResult($card)) {
            $this->cardToken   = $card->getCardToken();
            $this->cardUserKey = $card->getCardUserKey();

            // Update user card key *******
        }

        return $result;
    }

    public function insertCard($cardUserKey, $cardInfo)
    {
        if (empty($cardUserKey) || empty($cardInfo)) {
            return FALSE;
        }

        $request = new Request\CreateCardRequest();
        $request->setLocale(Model\Locale::TR);
        $request->setConversationId(time());
        $request->setCardUserKey($cardUserKey);

        $cardInformation = new Model\CardInformation();
        $cardInformation->setCardAlias($cardInfo['card_holder']);
        $cardInformation->setCardHolderName($cardInfo['card_holder']);
        $cardInformation->setCardNumber($cardInfo['card_number']);
        $cardInformation->setExpireMonth($cardInfo['exp_month']);
        $cardInformation->setExpireYear($cardInfo['exp_year']);
        $request->setCard($cardInformation);

        $card = Model\Card::create($request, self::getConfig());

        if ($result = $this->_getResult($card)) {
            $this->cardToken   = $card->getCardToken();
            $this->cardUserKey = $card->getCardUserKey();
        }

        return $result;
    }

    public function confirmProduct($paymentTransactionId)
    {
        $request = new Request\CreateApprovalRequest();
        $request->setLocale(Model\Locale::TR);
        $request->setConversationId(time());
        $request->setPaymentTransactionId($paymentTransactionId);
        $approval = Model\Approval::create($request, self::getConfig());

        return $this->_getResult($approval);
    }

    /**
     * @param $fraudStatus
     *
     * @return bool
     */
    protected function fraudCheck($fraudStatus)
    {
        switch ($fraudStatus) {
            case self::FRAUD_CONFIRMED:
            case self::FRAUD_CONFIRM_WAITING:
                return TRUE;
            case self::FRAUD_FAILED:
                return FALSE;
            default:
                return FALSE;
        }
    }

    /**
     * Calculate discount value from discount code
     *
     * @param string $discountCode
     * @param float $price The price that we want to calculate the discount on it.
     * @param $productType
     */
    public function setDiscountValue($discountCode, $price, $productType)
    {
        if (!empty($discountCode)) {
            // Discount implementation
        }
    }

    protected function _getBasketItemCommission($price)
    {
        if ($price <= 0) {
            return FALSE;
        }

        return $price - ($price * self::BASKET_ITEM_COMMISSION);
    }
}

send_payment_request.php

$iyzicoPayment = new IyzicoPayment(
    config_item('iyzicoApiKey'),
    config_item('iyzicoSecretKey'),
    config_item('iyzicoBaseUrl')
);
$products[]    = [
    'product_id'       => 1,
    'product_name'     => 'Test product',
    'product_category' => 'Test Category',
    'product_price'    => 1,
];

$paymentInfo = [
    'price'        => 1,
    'paidPrice'    => 1,
    'installment'  => 1,
    'registerCard' => FALSE,
];

$cardInfo = [
    'card_full_name' => '',
    'card_number'    => 'xxxxxxxxxxxxxxxx',
    'expire_date'    => 'xx/xxxx',
    'cvv'            => xxx,
    'installment'    => 1,
    'buying_policy'  => TRUE,
    '3d_payment'     => TRUE,
];

$billingInfo = [
    'id'            => 1,
    'name'          => 'John',
    'sur_name'      => 'Doe',
    'gsm_no'        => 'xxxxxxxxxx',
    'email'         => 'john.doe@example.com',
    'country_label' => '[Country]',
    'city_label'    => '[City]',
    'address'       => '[Address]',
    'national_id'   => '[NationalId]',
];

$result = $iyzicoPayment->payment($products, $paymentInfo, $cardInfo, $billingInfo, '[CallbackUrl]');

// Result of request
echo $result;
// Print errors if exist
print_r($iyzicoPayment->getErrors());
// Echo html content of 3DS payment comes from iyzico
echo $iyzicoPayment->htmlContent;

I know this class is really huge and is not really understandable but i added this here because yesterday one of my friends asked something like this because of iyzico docs is really confusable and not understandable. Hope this code help someone.
NOTE: I suggest you to not to use this code for production.