As long as the owner of the billing method authorized you to use it, you should be able to add it to your account. If any issues arise, Upwork team will notify you directly.
It looks like the charge on your card keeps getting declined. Please contact your card-issuing bank for more information about the specific charge decline and confirm if they allow recurring transactions on their cards as Upwork payments are classified as ‘recurring’.
I would recommend checking with your bank if your account is enabled for international charges. I also checked your account and I can see that you`ve already created a ticket. Rest assured, our team will assist you further directly on your ticket. Thank you.