I am unable to add cards to Apple Wallet

Please logout of your Apple ID, do a forced restart and then log back into your Apple ID. Links are below for reference and assistance.

Has the Apple Card Mastercard ever been in your Wallet before? If so, it may be in Previous Cards in your Apple Wallet app. Please follow the path below,

iPhone > Wallet app > tap Plus+ symbol in upper right corner > Available Cards > Previous Cards > it may take a minute or two for previous cards to appear, if Apple Card appears, tap card and follow any instructions.

Sign out of iCloud on your iPhone, iPad, Apple TV, or Mac - Apple Support

Force restart iPhone - Apple Support

You cannot add your Apple Card Mastercard to Apple Wallet, is that correct?