How to limit user action radius in X11 terminal server?

Question

linux

Good afternoon.
Please tell me the solution to the issue.
There is a terminal server on X11RDP.
I would like to limit the user's options.
Remove unnecessary shortcuts from the screen, prohibit the launch of all programs except Firefox. And so that Firefox starts automatically when you enter the session.
Where is it all set up? xsession?

Answer 1

KDE kiosk mode