I have a service where I can check if transaction with ID = xxxx is paid, let us say it's a sort of API. The problem is that my transaction is not processed momentary, it can take some time to process it, so it is possible that I have to check it few times in few hours after transaction.
Again: the essence of my question is how to deal with this situation, when my payment provider requires a pull, not giving a push to my thirytbees shop.