The cerascreen discount codes are usually only reedemable once and only for one specific product. The fine print directly below the coupon code lists the corresponding product. After you have decided which products you want to order, you can view them in your shopping cart. After agreeing to the conditions of use and sale you can continue to checkout. Here you can enter the discount code in the field provided (see picture).
Afterwards please click on the button Apply.
If this has not solved your problem, please contact us by email at email@example.com.