AUTOMATION #DISPLAY

xrandr

The X Server RandR extension provides automatic discovery of modes (resolutions, refresh rates, …)
and]the ability to configure output dynamically.

Changes made using xrandr will only last until you log out or restart the system.
To make changes persistently, use the xorg.conf configuration files for Xorg X server (run man xorg.conf for details on how to create a xorg.conf file)

You can also use the ~/.xprofile file (add xrandr commands in it), however, there are some disadvantages of using this method, one is that this script is read fairly late in the startup process, thus it will not alter the resolution of the display manager (if you use one e.g lightdm).

# show active monitors + settings
xrandr --listactivemonitors

# show all availble resolutions that can be set per available monitor :
xrandr

# `--mode`  :  set the resolution for a screen for A monitor  
xrandr --output DP-1 --mode 1920x1080

# `--rate`  :   set the refresh rate 

# to arrange your screens  relatively to each other.
# `--left-of`, `--right-of`, `--above`, `--below`, and `--same-as` 
xrandr --output DP-1 --left-of eDP-1

LAPWM2 config

xrandr --listactivemonitors 

 0: +*eDP-1 1366/344x768/193+1920+312  eDP-1
 1: +DP-1 1920/521x1080/293+0+0  DP-1             ### niet vermeld : 60 Hz

Add Missing or Set Custom Display Resolution(s) with xrandr

see https://www.tecmint.com/set-display-screen-resolution-in-ubuntu/ , second part

not installed ?!

# SPECIFIC FOR GNOME 
gnome-xrandr