Go to Settings, tap your name, and select iTunes & App Store.
- Tap your Apple ID, then tap to view Apple ID.
- Sign in using FaceID, Touch ID or by typing in your password. If you need help remembering your password, we can help you.
- Tap “Manage Payments”, then tap “Add Payment Method” then select Mobile Phone.
Your account will now charge all future purchases to your mobile phone bill.