Recently, apple account ID is associated with apple wallet app, and apple account ID is allowed to be updated Previously, if you received an app store or apple store gift card, you need to add an apple account to the app store or apple store app. Now users can add new gift cards to Apple account in the wallet app.
To add a card, open the wallet application and click "add Apple account" under "available cards". You can add a gift card as long as you have an apple account card.
Once added, you can view your apple account balance directly from the wallet app and use it to buy Apple products, apps, games and music. In the apple store, it works the same way as any other card in the wallet app. Apple account card replaces the iTunes pass that was available a long time ago.