Can I am at either a Walmart gift card or a target or a Amazon gift card to my Apple wallet

You can add any gift cards to your Apple Wallet IF THE GIFT CARD PROVIDER ALLOWS IT. For example, Dunkin' Donuts and Starbucks allow it.

Furthermore, I do not believe that any of the three that you mentioned allow their Gift/Loyalty cards to be added to Apple Wallet. This is because these merchants have their own apps and wallet section. For further clarification, contact those merchants and confirm.

Axel F.

As far as I know, the wallet payment methods can only be credit cards and debit cards