I purchased Sapphire Radeon NITRO + RX 580 8GB GDDR5 from NEWEGG
I got the GIFT Coupon Code
I sent the AMD Rewards to fill out the desired form to receive the game coupon, waited a week, but did not receive any email
Help us to use game coupons
You are gonna want to come here.
https://community.amd.com/thread/235480