On this good occasion, it would be nice if I introduce you to a new payment processor for the self-hosted category "Payram" (I mean the brand in my signature space). I have not measured how reliable this service is (I have not used it yet), but it seems to fit your requirements.
By the way, they have active support and a dedicated thread on this forum that I think will help you get started or just get a more complete explanation.
Good luck.

https://bitcointalk.org/index.php?topic=5540530.0