I have tried to install jitsi from stable, testing and nightly repos, but every time I did not see screenshare button. I know I needed special extension, but I got feeling that after 72 Chrome it is not needed anymore (my chrome is in recent 72).
When I run in docker, extension is not needed and I can see the button, but we experience connectivity issues when 3 more participants join (JVB Failed to set the TL0PICIDX of a VP8 packet)
I tried firefox as well without docker, screen share button there, but does not work, other site is not receiving.
We used to have older version of jitsi but with chrome upgrade to 71, screen share stop working and extension did not help. We are blocked and I am trying to find any workaround to have screen sharing working in our LAN
When I use https://meet.jit.si/ everything work just fine, I simply do not know how to reach similar stability in my own LAN
In any case I did not see on the left bottom panel share screen button. My browser is ok, because it works on docker and your meet.jit.si url. I cannot see any error in development tools. I used Ubuntu 18 and 16, on plain vagrant instance (“bento/ubuntu-16.04”)