Well, it's a coupon for a movie you can get online apparently (or video game, or whatever it is). What you do is, there should be a website on the coupon itself, so go to the website and there should also be a code on the coupon. Enter the code where it says on the website to enter the code and you should get Forever 21 for free or discounted (again, whatever it says on the coupon)
If it's a code to get a coupon for Forever 21, again it should have a website on the coupon itself. You go to that website, and go to where you enter the code. Enter the code, and bam, you got a coupon for Forever 21!
Either way, you're going to go to a website and enter a code...at least I'm 90% positive.
This is a coupon with a website on it. What you need to use this coupon is to visit that website and enter the code in order to be able to get the coupon or get the deal that is provided. Visit http://www.coupons.com/coupon-codes/forever-21/ to see how the coupons work.