App Store server notifications provide real-time updates on a subscriber’s status, so you can create customized user experiences. The following new notifications are now available in the App Store sandbox environment and you can use them in production later this year:

DID_RENEW lets you know when a subscriber successfully auto-renews.
PRICE_INCREASE_CONSENT lets you know when the App Store starts asking users to agree to your subscription’s new price, so you can remind them of your service’s value as encouragement to stay subscribed.

In addition, the following will be deprecated in the App Store sandbox environment in November 2020: RENEWAL notifications and these top-level objects: latest_receipt, latest_receipt_info, latest_expired_receipt, and latest_expired_receipt_info. Update your code to continue providing a seamless user experience.
Learn more about App Store server notifications