Can I use the attached weapons on the Dewbauchee JB 700?

I purchased the Dewbauchee Jb 700 for $305,000 but the guns don’t work. However, it’s also on Warstock cache and carry website for $1,470,000. What’s the difference? If I purchase the million dollar Dewbauchee JB 700 will the guns work? Also, can I use the guns outside of online missions?

The JB700 is a decommissioned version of the car you can buy from Legendary Motorsports, meaning the weapons don't work. But, the JB700W, is the weaponized version from War Stock Cache and Carry.

The GTA Online section for the Wiki says:

The JB 700W can be modified with a small set of weapons, which improve its defensive capabilities to a certain extent:

• It can equip two driver-controlled machine guns on its front, which perform the same as those of vehicles, such as the Blazer Aqua and Ruiner 2000, providing decent firepower against players and vehicles with none or light armour, but will struggle with heavily-armoured vehicles.
• The vehicle has the option to install Proximity Mines. Unlike Weaponized Vehicles added in the Gunrunning update and the Arena War vehicles from the Arena War update, the vehicle has two different Proximity Mine choices: Spike and Slick;
  • The Spike option (dark blue flashing light) bursts the tyres of vehicles passing over or near it, as well as dealing a small amount of damage to the vehicle, mainly affecting the vehicle's windows, but otherwise dealing no damage or force. The mine does not burst vehicles with bulletproof tyres installed.
  • The Slick option (green flashing light) bursts a large amount of oil on the surface, causing vehicles passing over it to lose control. This deals no damage to both vehicles or players.