Are you using our pi image? There it should be auto detected and start as soon as you plug it in. No github required here and no setup, just add it in server webcam (add webcam and at bottom select and assign it).
In ssh you see video devices with
ls /dev/v4l/by-id/
If it changes after plugging it in you know the device and that it is supported (should be have several logitechs working)
