It won’t allow me to add my navy fed card to apple pay

See the following Apple articles:

Set up Apple Pay

Set up Apple Pay - Apple Support

Payment methods you can use with your Apple ID

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

Countries and regions that support Apple Pay

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

Apple Pay participating banks in Africa, Europe, and the Middle East

Apple Pay participating banks in Africa, Europe, and the Middle East - Apple Support

If you can't add a card to Apple Wallet to use with Apple Pay

If you can't add a card to Apple Wallet to use with Apple Pay - Apple Support