When I enter my coupon code at the end of my booking, the amount of the coupon is not deducted from the total to be paid, why?

In fact, only the amount of the coupon appears, but don't worry, the amount debited will be reduced by the amount of the coupon.
You will be able to check this on the payment confirmation that you will receive at the end of the payment process. If you still have any doubts, please do not hesitate to contact us.