How to add a card as a payment method?
To add a card as a payment method:
Tap the Account tab on your Bitstack home screen
Press on Payment methods
Press on Add a payment method
Enter your card details
Press on Save
Complete an additional verification step (3DS) with the card issuer
Note: Your card issuer may ask to verify your card with 3D Secure.
Are American Express cards accepted on Bitstack? (AMEX)
It is not currently possible to buy Bitcoin directly with your American Express card.
Instead, you can connect your AMEX account to track round-ups that will be debited to another bank card. This restriction comes directly from American Express, which blocks purchases on cryptocurrency platforms.