Apple notified App Store developers about subscription offer codes coming later this year. A subscription offer code is a unique, alphanumeric code deemed for one-time use, which will help developers to “acquire, retain, and win back subscribers.”
As mentioned on Apple’s developer site:
Later this year, you’ll be able to acquire, retain, and win back subscribers with subscription offer codes: unique, alphanumeric codes that provide free or discounted prices for auto-renewable subscriptions. Provide your one-time use codes digitally or offline at physical events, alongside products, and more. Customers on iOS 14 and iPadOS 14 and later can redeem offer codes on the App Store, through a one-time code redemption URL, or within your app if you’ve implemented the presentCodeRedemptionSheet API.
With new subscription offer codes launching in iOS 14 and iPadOS 14, customers will be able to access free or discounted prices for auto-renewable subscriptions on apps. The offer codes can be redeemed on the App Store through a URL, or within an app if it supports the API. It will help developers in promoting their apps at both digital and physical events, as more app businesses are switching to subscription models.
You can visit Apple’s developer site for more detailed information on App Store subscription offer codes.