The answer to this question depends on the reason the vehicle is not in use and the requirements of your insurance company.
If your vehicle is out of service for an extended period of time, you may want to consider insuring it against risks such as theft, fire or damage from the elements. This can be especially important if the vehicle is parked in an area where it is at risk of damage or theft, such as a low-traffic street or an unattended parking lot.
However, if your vehicle is simply parked for a short period of time, such as a repair or maintenance, your current insurance policy may already cover the above risks. It is important to check the terms and conditions of your insurance contract to see what is and is not covered.
In any case, it is always best to contact your insurance company to discuss your specific situation and ensure that you have the appropriate coverage for your vehicle not in use.