Adding a card to apple pay

I'm in the US. My region and everything is set to United States. I cannot add my amex card to apple pay/apple wallet, but my parents and sibling can. On the final step I get a pop up saying 'The region setting for this device cannot be used with Apple Pay.'. and it just gives me a prompt to 'Set Up Later'. I've already double checked the region, and I can use apple pay on its own with just the apple cash.