Create In-App-Purchase from App Store Connect page Ref
Guidelines for Choosing a Product ID
Uniqueness: The Product ID must be unique across all of your in-app purchases for that app. No two in-app purchase items within the same app can have the same Product ID.
Structure: Product IDs are typically structured in a way that makes them easy to identify and manage. A common practice is to use reverse domain name notation, similar to your app’s bundle identifier, but with additional detail to differentiate between different products. For example, if your app’s bundle identifier is com.example.myapp, you might structure your Product IDs like this:
- com.example.myapp.premiumupgrade
- com.example.myapp.removeads
- com.example.myapp.goldcoins100