How to use Magento 2 REST API using the official Stripe module

rest-example.php

<?php

function getAdminToken()
{
    $url = 'https://example.com/rest/default/V1/integration/admin/token';
    $data = [
        "username" => "user",
        "password" => "user_password"
    ];
    $data_string = json_encode($data);
    $curl = curl_init($url);
    curl_setopt($curl, CURLOPT_POST, true);
    curl_setopt($curl, CURLOPT_POSTFIELDS, $data_string);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($curl, CURLOPT_HTTPHEADER, array(
        'Content-Type: application/json',
        'Content-Length: ' . strlen($data_string)
    ));
    $response = curl_exec($curl);
    if ($response)
    {
        curl_close($curl);
        echo "Got token $response\n";
        return $response;
    }
    else
    {
        echo 'Curl error: ' . curl_error($curl);
        return false;
    }
}

function createCustomer($token)
{
    $url = 'https://example.com/rest/default/V1/customers';
    $data = [
      "customer" => [
        "email" => "jdoe@example.com",
        "firstname" => "Jane",
        "lastname" => "Doe",
        "addresses" => [[
          "defaultShipping" => true,
          "defaultBilling" => true,
          "firstname" => "Jane",
          "lastname" => "Doe",
          "region" => [
            "regionCode" => "NY",
            "region" => "New York",
            "regionId" => 43
          ],
          "postcode" => "10755",
          "street" => ["123 Oak Ave"],
          "city" => "Purchase",
          "telephone" => "512-555-1111",
          "countryId" => "US"
        ]]
      ],
      "password" => "Password1"
    ];
    $data_string = json_encode($data);
    $curl = curl_init($url);
    curl_setopt($curl, CURLOPT_POST, true);
    curl_setopt($curl, CURLOPT_POSTFIELDS, $data_string);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($curl, CURLOPT_HTTPHEADER, array(
        'Content-Type: application/json',
        'Authorization Bearer: ' . $token
    ));
    $response = curl_exec($curl);
    curl_close($curl);
    echo "Got customer $response\n";
    return json_decode($response, true);
}

function getCustomerToken()
{
    $url = 'https://example.com/rest/default/V1/integration/customer/token';
    $data = [
        "username" => "jdoe@example.com",
        "password" => "Password1"
    ];
    $data_string = json_encode($data);
    $curl = curl_init($url);
    curl_setopt($curl, CURLOPT_POST, true);
    curl_setopt($curl, CURLOPT_POSTFIELDS, $data_string);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($curl, CURLOPT_HTTPHEADER, array(
        'Content-Type: application/json',
    ));
    $response = curl_exec($curl);
    curl_close($curl);
    echo "Got customer token $response\n";
    return json_decode($response, true);
}

function createQuote($customerToken)
{
    $url = 'https://example.com/rest/default/V1/carts/mine';
    $data = '';
    $data_string = json_encode($data);
    $curl = curl_init($url);
    curl_setopt($curl, CURLOPT_POST, true);
    curl_setopt($curl, CURLOPT_POSTFIELDS, '');
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($curl, CURLOPT_HTTPHEADER, array(
        'Content-Type: application/json',
        'Authorization: Bearer ' . $customerToken
    ));
    $response = curl_exec($curl);
    curl_close($curl);
    echo "Got quote $response\n";
    return json_decode($response, true);
}

function addToCart($customerToken, $quoteId)
{
    $url = 'https://example.com/rest/default/V1/carts/mine/items';
    $data = [
      "cartItem" => [
        "sku" => "24-WB04",
        "qty" => 1,
        "quote_id" => "$quoteId"
      ]
    ];
    $data_string = json_encode($data);
    $curl = curl_init($url);
    curl_setopt($curl, CURLOPT_POST, true);
    curl_setopt($curl, CURLOPT_POSTFIELDS, $data_string);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($curl, CURLOPT_HTTPHEADER, array(
        'Content-Type: application/json',
        'Authorization: Bearer ' . $customerToken
    ));
    $response = curl_exec($curl);
    curl_close($curl);
    echo "Added to cart $response\n";
    return json_decode($response, true);
}

function estimateShipping($customerToken)
{
    $url = 'https://example.com/rest/default/V1/carts/mine/estimate-shipping-methods';
    $data = [
        "address" => [
          "region" => "New York",
          "region_id" => 43,
          "region_code" => "NY",
          "country_id" => "US",
          "street" => [
            "123 Oak Ave"
            ],
          "postcode" => "10577",
          "city" => "Purchase",
          "firstname" => "Jane",
          "lastname" => "Doe",
          "customer_id" => 4,
          "email" => "jdoe@example.com",
          "telephone" => "(512) 555-1111",
          "same_as_billing" => 1
      ]
    ];

    $data_string = json_encode($data);
    $curl = curl_init($url);
    curl_setopt($curl, CURLOPT_POST, true);
    curl_setopt($curl, CURLOPT_POSTFIELDS, $data_string);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($curl, CURLOPT_HTTPHEADER, array(
        'Content-Type: application/json',
        'Authorization: Bearer ' . $customerToken
    ));
    $response = curl_exec($curl);
    curl_close($curl);
    echo "Estimated shipping $response\n";
    return json_decode($response, true);
}

function setShippingAndBilling($customerToken)
{
    $url = 'https://example.com/rest/default/V1/carts/mine/shipping-information';
    $data = [
        "addressInformation" => [
            "shipping_address" => [
                "region" => "New York",
                "region_id" => 43,
                "region_code" => "NY",
                "country_id" => "US",
                "street" => [
                    "123 Oak Ave"
                ],
                "postcode" => "10577",
                "city" => "Purchase",
                "firstname" => "Jane",
                "lastname" => "Doe",
                "email" => "jdoe@example.com",
                "telephone" => "512-555-1111"
            ],
            "billing_address" => [
                "region" => "New York",
                "region_id" => 43,
                "region_code" => "NY",
                "country_id" => "US",
                "street" => [
                    "123 Oak Ave"
                ],
                "postcode" => "10577",
                "city" => "Purchase",
                "firstname" => "Jane",
                "lastname" => "Doe",
                "email" => "jdoe@example.com",
                "telephone" => "512-555-1111"
            ],
            "shipping_carrier_code" => "tablerate",
            "shipping_method_code" => "bestway"
        ]
    ];

    $data_string = json_encode($data);
    $curl = curl_init($url);
    curl_setopt($curl, CURLOPT_POST, true);
    curl_setopt($curl, CURLOPT_POSTFIELDS, $data_string);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($curl, CURLOPT_HTTPHEADER, array(
        'Content-Type: application/json',
        'Authorization: Bearer ' . $customerToken
    ));
    $response = curl_exec($curl);
    curl_close($curl);
    echo "Set billing and shipping $response\n";
    return json_decode($response, true);
}


function sendPaymentInformation($customerToken)
{
    $url = 'https://example.com/rest/default/V1/carts/mine/payment-information';
    $data = [
        "paymentMethod" => [
            "method" => "stripe_payments",
            "additional_data" => [
                "cc_stripejs_token" => "pm_card_visa" // Use pm_card_threeDSecureRequired for 3DS authentication
            ]
        ],
        "billing_address" => [
            "email" => "jdoe@example.com",
            "region" => "New York",
            "region_id" => 43,
            "region_code" => "NY",
            "country_id" => "US",
            "street" => ["123 Oak Ave"],
            "postcode" => "10577",
            "city" => "Purchase",
            "telephone" => "512-555-1111",
            "firstname" => "Jane",
            "lastname" => "Doe"
        ]
    ];

    $data_string = json_encode($data);
    $curl = curl_init($url);
    curl_setopt($curl, CURLOPT_POST, true);
    curl_setopt($curl, CURLOPT_POSTFIELDS, $data_string);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($curl, CURLOPT_HTTPHEADER, array(
        'Content-Type: application/json',
        'Authorization: Bearer ' . $customerToken
    ));
    $response = curl_exec($curl);
    curl_close($curl);
    echo "Set billing and shipping $response\n";
    return json_decode($response, true);
}

$token = getAdminToken();
if ($token === FALSE) { die('Error getting admin token'); }

$customer = createCustomer($token);

$customerToken = getCustomerToken();

$quoteId = createQuote($customerToken);

$cart = addToCart($customerToken, $quoteId);

$shipping = estimateShipping($customerToken);

$estimate = setShippingAndBilling($customerToken);

$payment = sendPaymentInformation($customerToken);

print_r($payment);