No. Your NETGEAR router is designed for continuous operation, so you can leave it turned on all the time. You don't need to turn your router off if you aren't using the Internet.
If your router is installed somewhere like a vacation home that is only used seasonally, and you don't have any smart IoT devices like cameras or appliances that need an Internet connection, you might want to turn your router off to save power when you aren't there. However, you can also leave your router turned on all the time if you prefer.
For more information about router power consumption, see How much power does my NETGEAR router use?