The Shelly Plus Plug S does not require an active WiFi connection to store and execute switching schedules "offline" in the device. As long as the schedules are stored in the device, they can be executed even without a WiFi connection. You can therefore use the plug to restart your router automatically by setting the switching times accordingly.

However, to configure the switching times, you must first establish a WiFi connection to access the device's web interface and make the settings.