current screen resolution is not OK for me.i like to change to a different resolution,But the drop down list is limited to only 3 resolution.how to add a custom resolution.i tried xrandr commands,gives error
Added screen, workstation, x11-wayland-transition
Hi there, welcome to 
!
Can you give us some system infos? It is likely you use Wayland, which explains why xrandr has no output.
Under your system info page, you should see some more infos.
What is the native resolution of your display?
Added fractional-scaling, wayland