Steam for Linux: VirtualHere as purchased through Steam quits immediately; no GUI or errors

I've been trying to get my PC to recognise a webcam so that I can use non-steam software like Zoom and Skype from the living room rather than my desk. While I've been through the suggested routes (sharing the device through the Steam Link, then starting streaming), nothing appears as recognised on the computer.
I purchased the VirtualHere software through Steam, but when I click on it to run, it says 'running' for maybe half a second and then goes back to 'launch'. No error messages are given, no GUI appears.
What am I doing wrong?

#2

OK im a bit confused. "Steam for Linux" and trying this on your PC?

Can you breifly explain where the virtualhere server is running and what operating system you are using on the server side (the side that the usb device is physically plugged into) and where the virtualhere client is running (the remote side where you want to use the webcam etc virtually)