How to make a paid subscription to a wordpress site without plugins, well, or almost without them?

Question

Monetization

How can I implement a paid subscription to a wordpress site without the use of plugins, or almost without them, because. all plugins that accept payment through Russian systems (kiwi, yandex, etc.) are paid + learning how to do such a thing is very cool, at least for me.
What to use for this? How it works?

Answer 1

Yandex Money, notifications via http + WP-CLI. If rough.