• Changed command /fj set [jetpack] to /fj set [jetpack] <Fuel>
• Changed command /fj [get/give] (Player) [jetpack] to /fj [get/give] (Player) [jetpack] <Fuel>
• Added new permission .use and .refuel (example: fjetpack.vip.use to use jetpack only and can't refuel without permission fjetpack.vip.refuel)
• Added new support version 1.18

You can use both version for 1.8.x-1.16.x

for 1.17.x use from github version here