I need a very simple method for non-advanced users to share each other's screen explicitly when they need help. They're running XFCE on Manjaro and the machines involved are using Tailscale. Edit: SSH access is also available, with key authentication.
I need something super simple because they are remote from me and from each other and any graphical setup will have to be assisted sight-unseen over phone. So ideally just (1) install something (which I can do for them over SSH), (2) pick something from the Applications menu and maybe (3) press a big "START" button.
It's also ok-ish if the remote capability is present all the time and I can connect without their explicit permission, but you can see why it would be best if they did something to enable it...
I've been looking for a solution but all I find is stuff that's way too complicated OR starts a new desktop session instead of showing the current one.
Edited: to clarify I'm not the one who will be remoting-in and to mention SSH is available.
TIA
Not open source, but AnyDesk is another option that does exactly what you want.
There was a Flatpak, but the maintainer quit, so, you'll probably have to install it directly from their official site.
Anyway, RustDesk, as mentioned by other comment, is essentially the open source alternative to AnyDesk, so maybe look into that first.