FAPI.UI.showPayment why is there no API_callback when closing the successful purchase dialog?

Question

JavaScript

I ran into such a problem: a purchase of goods is made in the OK application, moreover, without payment confirmation. A dialog is shown on the OK side stating that the purchase was successfully completed. The dialog has a large green "CLOSE" button, which, when clicked, calls API_callback with the "showPayment" method. But the window still has a "cross" as a button to close the window, and if you close through it, then there is no API_callback and, as a result, there is no way to process the payment on the client. How to deal with it?

Answer 1

This question torments all OK developers. When the window is closed through the "cross", the message is not sent inside the application frame.
Options:
1) through checking on the server side by timeout
2) use websockets and receive notification from the server side.