I am trying to deploy an app using fly.io. But i can’t add credit info or buy credits. what to do
Do you mean you tried to add the info, and that failed (e.g a card error)? Or you have no credit card to add?
Only if you have no credit card, that is a problem. Fly requires one (to prevent abuse), even though they won’t bill it if you stay within the free allowance.
Credit card declined. When using debit card to buy credits. it says"we are unable to authenticate your payment"
Ah. I can’t offer any help with that I’m afraid. Assuming Fly still uses Stripe for handling payments, generally they don’t say why an error has happened. Fly calls the Stripe API → Stripe API returns “no”, and there is little Fly can do at that point.
It may be worth contacting your bank to see if they blocked the payment. Only sometimes when you use a card for a new purpose, especially if the company is in another country, banks can decline the payment out of caution. You may need to tell them it’s fine, it was you, at which point the payment may succeed. Other than that, not sure.