You absolutely can! This setup makes most sense if you need to keep your router to access some of its features. Add Plume to your existing network setup by hardwiring one of the Pods to the router. Plume's networking mode is set to Auto by default to allow Plume to select the appropriate networking mode for you.
In "Auto" mode, Plume selects "Router" or "Bridge" mode depending on what type of device (mode/ router/ combo) you connected your Pod to and whether that device is managing your network already.
If Plume is set to "Router" and you are still your existing router to manage the network, you will want to change this to "Auto" mode using your iOS or Android app once all of your pods have been claimed and your Plume network is up and running.
Please note that switching the Plume mode from "Router" to "Auto" mode will cause all of your Pods to reboot.
After setting up Plume with your existing router, do not forget to turn off the WiFi signal on your original router after you've set up Plume. It is important that you use a different name and password for your Plume WiFi network to make sure that your devices don't get confused and try to switch back and forth between your new Plume network and your older router's network.