If you pre-order Dying Light: The Beast before its launch on August 22, 2025, the Hero of Harran bundle will be added automatically to your account. You will find it in your game library and might need to manually download it once the game launches, depending on the platform you play on.
There are currently no plans to release the contents of the Hero of Harran-bundle at a later time. But you get it at no additional cost if you pre-order Dying Light: The Beast before August 22, 2025.
Also, all owners of Dying Light 2: Stay Human Ultimate Edition will get the Hero of Harran bundle at no extra cost - no action necessary. Once the game releases, you will have access to the bonus content.