It depends on which device you are using.
For some devices, this feature can be found in the unit’s Setbox.
Please check info about Setbox here. – https://help.gurtam.space/en/article/tools
Also for some devices, it is possible to block vehicles from the unit card on the “Units” tab.
Please specify what type of device (model) do you use?
Also keep in mind that the device must be properly connected for the commands to work correctly, test the commands only when your vehicle is stationary, as there have been cases when the engine was accidentally turned off while driving. Be careful.