A discount coupon is a code that, once validated in your shopping cart, gives you a discount. If you have a discount coupon, it means we sent it to you by email as part of a special promotion or discount, or you saw it on our homepage, personalization page, or social media.

In that lucky case, in the shopping cart, validate it where it says "You have a promotional code". 

If it is correct, the discount will be applied automatically.