Adding a promotional code triggers the creation of one or more coupons corresponding to your offer.
To add a promotional code, simply:
1) Tap on the "Promotion Code" section from the application menu.
2) Enter the code in capital letters.
3) Click on "OK".
Once your promotional code has been validated, you can consult the status of your coupons by tapping on "Find out more" or via "Payment methods" then "Coupons" in the application menu.