LiveOrder POC for `Login` and `Add to Cart with Promocode`

suitecommerce.php

<?php
/*#############################
* Developer: Mohammad Sharaf Ali
* Designation: Sr. SE
* Version: 1.0
*/#############################

class SuiteCommerce
{
    protected $cookie;

    public function __construct() {
        $this->cookie = '';
    }

    public function initCurlRequest($reqType, $reqURL, $reqBody = '', $headers = []) {
        $ch = curl_init();
        
        curl_setopt($ch, CURLOPT_URL, $reqURL);
        curl_setopt($ch, CURLOPT_FRESH_CONNECT, true);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($ch, CURLOPT_CUSTOMREQUEST, $reqType);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $reqBody);
        curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
        curl_setopt($ch, CURLOPT_HEADER, true);
        
       	$body = curl_exec($ch);
    
       	// extract header
       	$headerSize = curl_getinfo($ch, CURLINFO_HEADER_SIZE);
    	$header = substr($body, 0, $headerSize);
    	$header = $this->getHeaders($header);
    
    	// extract body
    	$body = substr($body, $headerSize);
    
        curl_close($ch);
        
        return [$header, $body];
    }

    public function getHeaders($respHeaders) {
        $headers = [];
    
        $headerText = substr($respHeaders, 0, strpos($respHeaders, "\r\n\r\n"));
    
        foreach (explode("\r\n", $headerText) as $i => $line) {
            if ($i === 0) {
                $headers['http_code'] = $line;
            } else {
                list($key, $value) = explode(': ', $line);

                // prevent duplicate key(s)
                if (!isset($headers[$key])) {
                    $headers[$key] = $value;
                }
            }
        }
    
        return $headers;
    }

    public function doLogin() {
        $reqBody = [
            'email' => 'your_ns_email',
            'password' => 'your_ns_pass',
            'redirect' => 'false'
        ];
        $headers = [
            'Content-Type: application/json;charset=utf-8',
        ];

        list($header) = $this->initCurlRequest(
            'POST',
            'https://checkout.na0.netsuite.com/c.your_ns_acc/scs/services/Account.Login.Service.ss?n=2&c=your_ns_acc',
            json_encode($reqBody),
            $headers
        );

        $this->cookie = explode(';', trim($header['Set-Cookie']))[0];
    }

    public function doLogout() {;
        $reqBody = '';
        $headers = array(
            'Cookie: ' . $this->cookie
        );

        $this->initCurlRequest(
            'GET',
            'https://checkout.na0.netsuite.com/c.your_ns_acc/scs/logOut.ssp?n=2&logoff=T',
            $reqBody,
            $headers
        );
    }

    public function doAddToCart() {
        $reqBody = [
            'item' => [
                'internalid' => 61068,
                'type' => 'Assembly',
            ],
            'quantity' => 1,
            'options' => [],
            'location' => '',
            'fulfillmentChoice' => 'ship',
            'freeGift' => false
        ];
        $headers = [
            'Content-Type: application/json;charset=utf-8',
            'Cookie: ' . $this->cookie
        ];

        $this->initCurlRequest(
            'POST',
            'http://your_domain/scs/services/LiveOrder.Line.Service.ss?c=your_ns_acc&n=2',
            json_encode($reqBody),
            $headers
        );
    }
}

$suiteCommerce = new SuiteCommerce();

$suiteCommerce->doLogin();
$suiteCommerce->doAddToCart();
$suiteCommerce->doLogout();

echo 'Script Execution Completed!';