Apple does have a rule about providing an in-app purchase option, although I believe they don’t require that be the only way to make the purchase. I think Appl

Apple does have a rule about providing an in-app purchase option, although I believe they don’t require that be the only way to make the purchase. I think Apple tries to distinguish between apps that provide access to content which you subscribe to (so-called “Reader” apps) versus apps where the service is the app itself. If the service is the app itself, then they want all apps to be sold directly through the App Store. If the app is a Reader for a content subscription, then they allow selling the content subscription separately. I’m not sure it’s evenly enforced, but I think that’s their intent and stated policy which they are trying to enforce here.