//API isteğini göndereceğiniz Endpoint URL değeri
$api_url =
'https://yourSubDomain.payfull.com/integration/api/v1';    //Payfull hesabınız içerisinde oluştuduğunuz API hesabına ait "Üye İşyeri Şifresi" değeri.

   $merchantPassword = 'your merchant password';
‍
//parametrelerinizi oluşturduğunuz dizi. 
                        $params = array(                  
                     "merchant"        => 'your merchant name',
                       "type"            => 'Sale',          
                        "total"            => '1.01',
                        "cc_token"         => 'A5NVH5VFTXE3XT3DUTVJMT
D2BR2U7K5LBS2UNOXFTA5W2BII',
                       "currency"        => 'TRY',
                     "installments"       => '1'
                      "language"       => 'tr'
                      "client_ip"       => '192.168.1.1'
                      "bank_id"       => 'Akbank'
                      "gateway"       => '160'
                      "customer_firstname"       => 'ALI'
                      "customer_lastname"       => 'MUHAMAD'
                      "customer_email"       => 'alitestemail@gmail.com'
                      "customer_tc"       => '12590326514'
                      "passive_data"       => write here what you like4'
‍
                        );
‍
                     // Hash kodu üretme yöntemi.
                        ksort($params);
                     $hashString = "";
                     foreach ($params as $key=>$val) {                             
                      $l = mb_strlen($val);  
                      if($l) $hashString .= $l . $val;
                       }


                       $params["hash"] = hash_hmac("sha256", $hashString, $merchantPassword);
‍
                       $ch = curl_init();
                       curl_setopt($ch, CURLOPT_URL, $api_url);            
                        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
                        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
                        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);                                               curl_setopt($ch, CURLOPT_TIMEOUT, 60);      
                        curl_setopt($ch, CURLOPT_POST, 1);  
                        curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($params));

                         $response = curl_exec($ch);                    

           $curlerrcode = curl_errno($ch);
           $curlerr = curl_error($ch);              

           var_dump(json_decode($response));