https://www.gamespot.com/articles/how-to-download-fortnite-android-its-trickier-than/1100-6461138/

Fortnite has launched on Android devices. The beta launched exclusively on Samsung devices last week, and now it's available on other Android platforms. However, you'll have to jump through a few hoops before you can jump from the battle bus.

Epic is using a special Fortnite Installer on the company's website, so you're not going to find what you're looking for in the Google Play Store like other mobile games. Searching for "Fortnite" or "Fortnite Battle Royale" won't get you anywhere. What type of Android device you're using will determine where and how you install the game.