Server notifications from Qiwi, how to get all data from a notification?

Question

Qiwi

Good afternoon. In what format do server notifications come? I set up Checkout Popup for p2p (Receiving transfers) and specified the address for receiving them. How can I pull out the comment field (I store a set of data necessary to complete the purchase in it). The documentation says that the data comes in the POST array. I understand the comment field will look like this $_POST['comment'] ? When trying to get any data from the post array, nothing happens, the array is empty. Please, if you don’t know the answer, don’t just throw a link to the documentation, I studied it, but I still don’t understand why it doesn’t work.
On Yandex money it was like this $_POST['label']; and in this field all the data that I indicated was stored. I
just thought maybe someone had already done this. and help me with a "live" example

Answer 1

Everything is indicated in the documentation: https://developer.qiwi.com/ru/qiwi-wallet-personal...