https://wccftech.com/fortnite-4-2-content-update-jetpacks/

Fortnite Battle Royale is finally getting its damn jetpacks. Originally scheduled for a February release, the Jetpack was delayed for months due to unspecified “issues,” becoming something of an obsession for Fortnite fans. Hopefully the wait was worth it!

Epic has created the new Backpack inventory slot for the Jetpack, which is a single-use item – once its fuel has been fully consumed, it will explode, and you’ll have to search treasure chests for another. Activiating the Jetpack is a simple matter of double jumping, and Targeting Mode will not be available while in the air.