Wallet supports passes and other gift based cards, but the gift card issuing merchant itself must support their cards being added to Wallet in return. Some merchants may require you download their App, to redeem their card, and then add it to wallet from the App.
Consequently, how do I add a gift card to my Apple Mail wallet?
In the wallet app, tap on “Edit Passes” at the bottom of the screen. On the next screen tap on “Scan Code.” Scan the QR code on the back of the gift card, and you’ll be asked if you want to open Safari. Do that, and the card will show up and be added to wallet.
Tap the menu button , then tap Account. Tap Redeem Gift Card or Code. Enter the 16-digit code. Then tap Redeem.
Just so, why can’t I add a Visa gift card to my Apple wallet?
Contact your card issuer to see if they support Apple Pay. Update to the latest version of iOS or iPadOS, watchOS, or macOS. Make sure that you are in a supported country or region. Check that your device is compatible with Apple Pay.