Permission denied error in payumoney integrating to opencart

I want to integrate the pay u money payment gateway in opencart platform. I have integrate the gateway but there is an issue while i am confirming the order.

You may visit to www.classyshopo.com and click to purchase order and tring to pay with pay u money, there is an error in pay u money, there is not any option for confirming the order.

You may use the registration user [email protected] and password as salimjani.

Please provide me the help for this issue.