Problem with paying classmates, what to do?

Question

Classmates

Hello!
There is a mobile application "Power of Darkness".
sdark.mobi
Link to the application: m.ok.ru/app/1127811072
Almost set up the application, but ran into a problem when paying for game currency for OK.
A purchase confirmation window appears. After pressing the "Order" button, the following error appears:
"The payment system is on maintenance and will work very soon.
Stay tuned!"
It's my fault? What to do in this case?

Answer 1

See an example of making a payment for HTML .
For a mobile application, there shouldn't be much difference.

Answer 2

The problem is that the callback link is configured incorrectly.
Throw someone an example of a link that should be inserted in the application settings.