Regarding the problem of modifying the resolution of ubuntu20.04

By default, dsiplay under settings cannot modify the resolution. Start setting up below.

The first step is to add the resolution (for later modification of configuration file parameters):

cvt 1920 1080

The second step is to check the supported resolutions:

xrandr

The third step is to modify the configuration file:

 Enter: sudo gedit /etc/profile

Add the following two lines of code at the end.

xrandr --newmode "1920x1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync
xrandr --addmode Virtual "1920x1080_60.00"

Step 4: Modify the resolution