How to check payment on Telegram bot API QIWI?

Question

PHP

In general, I am writing a telegram bot with Qiwi payment in PHP. Of course, I use MYSQL through ORM RedBeanPHP, API QIWI.
That is, when a person wants to replenish the balance, he is given a Qiwi number and a generated comment.
The generated comment, nickname, chat number is entered into the database.

Further, when he makes a payment, I need to somehow confirm it, that is, I need to select precisely this comment in the database that was generated. There was an idea to try to create a temporary variable, but the attempt was unsuccessful. If I search by an identifier, for example, a user name or by a chat number, then all possible transactions of this user will be loaded, which is not good, and again I will not achieve the proper result

I have already broken my whole head, how you can pull this whole thing up. Maybe I did not set the logic correctly?
Maybe I'm a fool or the skis don't go, but I'm asking for help, I don't understand how to correctly compare this, I know that the answer is close, but I already decided to ask here.