Another lesson in "Don't Use An App for things that should be a Website":
https://news.patreon.com/articles/understanding-apple-requirements-for-patreon
Basically, Apple is going to steal 30% of Patreon's money that's supposed to go to creators. Because... Apple. If it's an app and it's in their store, they will squeeze you for every penny they can get.
Note: Android isn't innocent in this, either. Use the website whenever you can.