afaik you have to get a voucher from the place you bought the game - then go to amdrewards.com + register/login and claim the Key via Voucher
I took a quick look.
Cannot find the exact model.
There is this: SAPPHIRE PULSE RADEON RX 5600XT BE 6GB GDDR6 192BITS OC (PN:11296-05-20G)
It is a BE version not OC.
However - bad news.
AMD "Raise the Game" promotions are only available with certain participating retailers.
Normally there are sdverts about it on the website and "Free Items" link with the GPU.
It does not seem like that retailer was/is participating.
That means no game codes.
Even if they are participating they often try to weasel out of it.
First 4 points for your convenience: