transaction_not_allowed
Transaction not allowed. The bank doesn't allow this type of transaction on the card, such as online or recurring charges.
Will retrying the charge work?
No. The same card will keep failing. You need the customer to give you a new payment method.
What to do about it
Ask the customer to contact their bank or switch cards. Common with some debit and prepaid cards.
What to tell your customer
Your bank doesn't allow this type of payment on your card. Contact them or use a different card.