Adding Online Payment to a Website

Hello, I have a website ([login to view URL] it is smm panel probably you have seen such scripts it is written in php. and in my country there is a payment service [login to view URL] they gave me APIs and payment service IDs So I need to integrate these payment to my site. The website should check whether the payment succesful if it is it should be added to user balance. Payment companys APIs <?php class Checkout { private $p_id; // Partner ID private $s_id; // Service ID private $key; // Service key private $o_id; // Order ID private $tr_id; // Transaction ID private $method; // Metod (account or code) private $amount; // Amount private $test; // Service regime status private $hash; // Encrypted info name public function __construct() { $this->p_id = xxxxx; //write your partner id here $this->s_id = xxxxx; //write your service id here $this->key = 'xxxxxxxxx'; //write your service key here $this->o_id = $_POST['o_id']; $this->tr_id= $_POST['transaction']; $this->method = $_POST['method']; $this->amount = $_POST['amount']; $this->test = $_POST['test']; $this->hash = $_POST['hash']; } public function result() { $hash = strtoupper(md5($this->p_id.$this->s_id.$this->o_id. $this->tr_id.$this->key)); if($hash == $this->hash) //if it is true 1, or 0 callback { if($this->test == '0')//If test regime off { //Write you base operation here //(For example: Add balance, add bonus) } echo '1'; } else { echo '0'; } } } if(!empty($_POST)) { $portmanat = new Checkout; $portmanat->result(); } ?> AND my Partner ID: 16235 Service ID: 12671 Service Key: burcu1