If you have a current app that does not use a server to validate receipts (Yes I know this is not reccomended), how can iOS purchases be migrated to revenuecat?
If the user initiates a restore purchase would this happen:
App checks revenuecat > sees no customer data > revenuecat checks apple > sees purchase > revenuecat creates customer info > sends info back to app.
For that you would follow the client side migration path that you can find here https://www.revenuecat.com/docs/migrating-existing-subscriptions#client-side-migration. That should sync the receipt with RevenueCat, and eventually all active paying customers should end up in the system.