Here are the most common reasons for failed transactions.
Some patients don't enter the OTP at all (and it times out)
Some patients don't get the OTP (either because they registered the wrong mobile number with the bank or the bank has an issue sending SMS at that time)
The card is blocked for online transactions
If they chose to pay using any of the over the counter options, there are instructions provided to them on what to do for Step 2
You can direct patients to message firstname.lastname@example.org next time. They also see the email in the bill.
They can simply send the error message screenshot, so we can advise on what to do.