If I publish on Google play, do I have to use their payment system, which takes 30% for myself?

Question

Game development

Good afternoon, I'm going to make a payment system for in-game purchases and donations in my application. And I read all sorts of nonsense on the Internet.
The game is made with Unity. In general, the question is higher.
In general, I'm thinking of making a login and wallet system on a separate site, and Unity will simply access the database of this site, is that good?
Will IOS market and Google play force me to use their payment systems and take half the money?
And also can anyone recommend Unity plugins for payment systems and their options?

Answer 1

We go: https://play.google.com/intl/ru/about/developer-co...
We find: https://play.google.com/intl/ru/about/monetization...
Conclusion: you can use own, but only in some cases.
In your case, they can get banned if you don't use the Google payment system :(