Sometimes, if you skip the verification step when adding your Digital Card to the wallet your card will say ‘Card Not Set Up’. In this case, you should-
1. Remove the card from the wallet
2. Add the card again from the shortcut in the Get My eCard app
3. During the wallet set up, make sure to complete verification by email.
Or, you can try to add your card to the Apple Wallet manually by following the instructions here. Your full card details can be found in the Get My eCard app by simply tapping on the image of your card.
If things still aren’t going to plan, you might see a ‘Card Not Added: Contact Card Issuer’ message. The registered location of your Apple ID may be causing the issue and these steps may help.