Adding an American Express gift card

See -> Payment methods you can use with your Apple ID

Payment methods you can use with your Apple ID – Apple Support (UK)

See the App Store & iTunes gift card, that you can use to purchase in App Store 7 iTunes Store: Apple Gift Card - Apple (UK)

For your American Express gift card, see -> https://www.amexgiftcard.com/frequently-asked-questions

• Your American Express eGift Card can also be used in-store to pay when added to digital wallets: Apple Pay®, . . .

See the following Apple articles:

Set up Apple Pay

Set up Apple Pay - Apple Support

Countries and regions that support Apple Pay

Countries and regions that support Apple Pay - Apple Support (EG)

Set up Apple Pay in Wallet on iPhone

Set up Apple Pay in Wallet on iPhone – Apple Support (UK)

Make purchases using Apple Pay

Make purchases using Apple Pay - Apple Support

Make contactless payments using Apple Pay on iPhone

Use Apple Pay for contactless payments on iPhone – Apple Support (UK)

Use Apple Pay in apps, App Clips, and Safari on iPhone

Use Apple Pay in apps, App Clips, and Safari on iPhone – Apple Support (UK)