Add weapons to cars

[Goliat_21]

Hi all
I want to put weapons on vehicles, like the ones in the tank.
The mod that I want to modify is this https://es.gta5-mods.com/vehicles/batmobile-mk2.
That batmobile has machine gun, rockets and tank turret
I would like to replace some of those weapons or add another
and I would like to know if anyone knows how to make those modifications