https://wccftech.com/how-to-unlock-the-exclusive-galaxy-skin-in-fortnite/

Shortly after they announced the Fortnite for Android beta program, Epic Games confirmed that all Galaxy Note 9 and Tab S4 users would receive an exclusive ‘Galaxy’ skin. The skin covers your character in stars and various other objects from outer space. To unlock the skin on both devices, you have to download and install the Fortnite Installer from Samsung’s Galaxy Apps store and not Epic Games’ website. Additionally, the skin can only be unlocked once per device.

If you preordered the Note 9 you are eligible to pick between a pair of wireless AKG headphones or a Fortnite gaming bundle of 15,000 VBucks and the Galaxy Skin. For those who picked the Fortnite bundle or here’s how to redeem the bundle and get your VBucks and the Galaxy Skin: