You need xdg-desktop-portal
. Its probably automatic in some environments but with sway I have to set it up manually. Its one of those annoying things I forget about whenever I set up a new machine.
Works for me, using Fedora with Plasma. Just fire it up in Brave, and install it as a PWA.
The one thing that bothers me is it can't tell if I'm at my machine when I'm not actively using it. People keep thinging I've bugered off from my desk.
Screen sharing from the browser usually works for me, but if ever it doesn't, as a workaround you can use OBS with a virtual webcam to share windows and screens as an overlay to the webcam stream. It's very easy.
