Download Rocket League on the Epic Games Store from September 23 through October 23, 2020 at 11AM Eastern Time and get a $10 Epic Coupon.
You’ll also receive the Sun Ray Boost and Hot Rocks Trail. To claim the Items, download Rocket League on Epic Games Store, launch Rocket League with the same Epic Games account, and the items will appear in your inventory.
If you are signed in with your Epic Games account or have linked your platform account to your Epic Games Account, you will have access to the Sun Ray Boost and Hot Rocks Trail on all linked platforms.
For more info check out the Epic Games Blog: Rocket League is Free to Play on Epic Games Store starting September 23