This will apply the promocode to the coupon code engine.
First validation is on Review page promocode Bar, in case user enters manually.
Rule:
In case the promocode is valid only on selected cards starting from a Bin Number, and the payment method is not valid according to Promocodes terms and conditions or user entered a invalid card number or entered a card number which is not received in the Promo response from backend, then a consent will be asked from the user to proceed with payment without any discount(promocode).
On payment page:
User based promocode will effect the Fare calculation. Bin number (XXXXXX-XXXXXXXXX) first 6 digits will be provided in API. Need to validate and match if the user entered eligible card number or not. Restriction message will be shown to the user “Promocode is invalid for this card, do you want to continue without Promocode or Retry with New Card no.” In case user continue without Back specific promocode, then by-default promocode (example: ATFLY) will apply automatically