Go to Samsung pay on top left you'll see three bar tap on it and then select Settings, on Settings scroll down and select profile, under Address Book select Register new address and add you current address after that it may let you add other cards.
Thank you ! No, i don't , but I just talked with a guy in the customer help who said that my cellphone was manufactured in U.S. so I can't add cards from another country. That's is strange and non sense.
Yes Samsung needs to update app and make sure we can add card from other places and other features. Then maybe your best option for now is to use other apps like Google pay or other.