I am using In-App Auto renewable subscription and testing in sandbox and also implemented server-to-server notification on my server.
What I want to clarify is, this auto renewal notification is available in live environment? ie, App Store send a notification to our server when the subscription renewing automatically in live environment?
Short answer: No, renewal events are not arriving via Apple Notifications on both environments. You have to calculate manually your expiration date and schedule validation on your behalf. However there are plenty of ready to go solutions, like our service.