If you purchased a title on the Epic Games Store but you can't download it, make sure the game has been released. We often have titles available for pre-purchase.
You can check when your pre-purchased game will be available to play by looking at the Available field for the title on the Epic Games Launcher.
If your game has been released and you still can't download it, check out this article for troubleshooting steps: Troubleshooting the Epic Games Launcher