The payment site should have a callback url or something right?

Exactly ! 🙂

from documentations: "On transaction success the URL address transferred in "urlStatus" parameter is used to send notification irrespective of whether the customer has been redirected to "urlReturn" or not. The notification is sent only for correct payments. The system does not send information on invalid or failed payments. The notification is sent in the JSON format."

Then just create a route handler ig, set the callback url to that, then you can do whatever you want with the data

ok, thankYOU ! am gonna to find info about it 🙂

can you give me some code exmpales. It seems to bede brand new for me, thanks

Are these not enough?
https://nextjs.org/docs/app/building-your-application/routing/route-handlers

if you say so it can be enough. Gonna to study 🙂 Thanks again

i just spoke with helpline this Payment system. And it is impossible to get this by routing. Sytutation looks like - after I fetch data at the first time, and get token system redirect client to exteranal link with payments. After succefully payment system send request viwht POST method to this URL. I cant fetch this data via Next.js and I need some backend to do this and make something like listening endpoint at the backend. Do you guys could reccomend some good back end for next.js?

it has to be something like server that is listening requests.