We have a mobile app so we sell subscriptions through the App/Play store (using RevenueCat to make our backend mumbo-jumbo a bit easier to handle! Definitely recommend them btw - saves a lot of time and their documentation is better than the stores')
@daniel_hunt4 I second that using RevenueCat as well, makes it a lot easier to collect in-app payments than the native apple StoreKit implementation. For web have used Stripe, was the smoothest integration in my opinion