SKU
The product identifier of an Apple In-App Purchase product you manage in your own system.
Declaration
string SKUDiscussion
Apps that use the Advanced Commerce API manage their own catalogs of Apple In-App Purchases. You assign a SKU to each product, along with other information such as the display name, description, and price.
The SKU value isn’t displayed to customers, and isn’t stored by App Store Connect.
A SKU can represent any type of Apple In-App Purchase product that your app offers, including products with a one-time charge, auto-renewable subscriptions, or bundles and items in subscriptions.