How To Redeem An Apple Gift Card On An IPhone Or IPad

From Errorwiki

Locate the 16-digit code on the back of your gift card. (You may need to peel or scratch off the label first).

Open the App Store on your device.

At the top right of the "Today" screen, apple.com/redeem tap the sign-in button, your photo, or your initials.

Tap "Redeem Gift Card or Code." (If you don’t see this, sign in with your Apple ID first.)

Tap "Use Camera" and follow the instructions on the screen to upload the card info instantly. You can also tap "Enter Code Manually," then follow the instructions on the screen to input the card info yourself.