You should never make payments using a barcode.

These days, such scams are happening. If anyone calls and sends a barcode, do not make any payment to them. They say it's your flash wallet and that you have an outstanding loan, but I never took any loan. They say to pay the loan even though it was supposed to be free. Even after all this, after I paid the loan, they keep calling repeatedly and harassing me, saying your number is still pending and not updated. Even after payment, they say you never took any loan. Beware of such frauds.