Since FS20 doesn't have an official in-game mod hub for mobile like FS22 does for PC/Consoles, you must manually edit the game files.
Navigate to the assets/data/vehicles or assets/data/characters folder. Fs 20 Batma Modu Mp3 Д°ndir
Replacing trucks with a Batmobile (like the classic 1989 version or the Tumbler). Since FS20 doesn't have an official in-game mod