If you use the "preview to projector/monitor" with an extra monitor, then you can share that screen in the teleconference. I've done that with zoom while movin

If you use the "preview to projector/monitor" with an extra monitor, then you can share that screen in the teleconference. I've done that with zoom while moving to online teaching these past weeks. I also got an idea from folks at the libre graphics track at SCaLE (southern California Linux expo) this year that you could use the preview feature but run the video out (eg HDMI) to a video capture device then back into your computer. I haven't tried that yet though.