کد PHP:
$parsian['secret'] = "12345678"; //change this secret code for each installation
$parsian['rates'] = array(
"IRT"=>10 , //Iran Toman
"IRR"=>1 , //Iran Rial
"USD"=>19000
); //these are exchange rates if you use multiple currency
$parsian['callback'] = "http://www.YOUR-SITE-ADDRESS.com/WHMCS-DIR/modules/gateways/callback/parsian.php";
$parsian['pin'] = "12345-98765"; //Parsian Bank Merchant PIN Code
$parsian['parsian'] = "https://www.pecco24.com:27635/pecpaymentgateway/eshopservice.asmx?wsdl";
$parsian['parsianget'] = "https://www.pecco24.com:27635/pecpaymentgateway/";
?>
callback باید آدرس کامل سایتتون باشه. دو خط آخر را هم به صورت بالا تغییر بدید.