sony a7

Hi, I have a problem with Sony Alpha 7 III DSLR Camera on Windows 11. I've connected my DSLR and set up the Imaging Edge app, I can see what the camera is capturing, everything seems to work, but when I try to use it via Zoom, Google Meet, Teams etc. it's not able to find it. Even the Camera app...

I am new to cameras and have been made an offer to swap something for a A7 with a 28-70mm lens, I was wondering what the estimated cost of those 2 paired together would be? and if it is good for a starter, many thanks :)