Can I not use my apple gift card to pay for my games?
I wish to use my apple gift card to pay for the extras in my games. Can it be used this way?
iPad, iPadOS 14
Question marked as
You should be able to use an Apple gift card for anything on the Apple Store, including the App Store.
If the game in question uses the App Store for in-game purchases, then you should be able to use a gift card balance to pay for it.
How to redeem your Apple Gift Card or App Store & iTunes gift card - Apple Support
If the game uses some system outside of the App Store, then you're out of luck.