If you received your Closed Beta code, here's how to redeem it on the Epic Games Website:
STEP 1: Go to the Epic Games Website here.
STEP 2: Hover your user icon on the top right of the website.
STEP 3: Select "Redeem Code".
STEP 4: Enter the received.
STEP 5: NOW INSTALL & ENJOY THE GAME!
*Make sure to download the Epic Games App here to be able to Install the game.
If you haven't registered yet...
Register to the Closed Beta at https://www.metalcore.gg.
(A few keys will be distributed every 24 hours, keep an eye on your emails & be patient. Maybe you'll be lucky enough to get one!)