Is it mandetory to display coupon discount on Apple Pay

I am building a functionality where I am offering some discount to user based on some coupon code. The management of Coupon I am handling at my website and after applying coupon user can see the updated pricing. Now if the user proceed with the payment using ApplePay as per Apple docs https://developer.apple.com/design/human-interface-guidelines/apple-pay

> Display the active coupon or promotional code, or give people a way to enter it. For example, if people can enter a code before the payment sheet appears, displaying it on the sheet can reassure them that the code works as they expect. Alternatively, allowing code entry on the payment sheet can be particularly beneficial in an express checkout flow.

Looking into this it is not clear to me weather it is a good practice to follow or a strict guideline. What could be the consequences if I don't show any coupon discount related information on ApplePay payment page