Use iPad as 2nd monitor of Ubuntu 24.04 LTS

I am trying to use xrandr and deskreen to use my iPad 9th gen as the 2nd screen of Ubuntu 24.04 LTS (X11).

❯ xrandrScreen 0: minimum 320 x 200, current 1366 x 768, maximum 16384 x 16384eDP-1 connected primary 1366x768+0+0 (normal left inverted right x axis y axis) 309mm x 173mm   1366x768      60.00*+  40.00     1280x720      60.00     1024x768      60.00     960x720       60.00     928x696       60.00     896x672       60.00     1024x576      60.00     960x600       60.00     960x540       60.00     800x600       60.00     840x525       60.00     864x486       60.00     700x525       60.00     800x450       60.00     640x512       60.00     700x450       60.00     640x480       60.00     720x405       60.00     684x384       60.00     640x360       60.00     512x384       60.00     512x288       60.00     480x270       60.00     400x300       60.00     432x243       60.00     320x240       60.00     360x202       60.00     320x180       60.00  HDMI-1 disconnected (normal left inverted right x axis y axis)

❯ xrandr --addmode HDMI-1 1366x768

❯ xrandrScreen 0: minimum 320 x 200, current 2732 x 768, maximum 16384 x 16384eDP-1 connected primary 1366x768+0+0 (normal left inverted right x axis y axis) 309mm x 173mm   1366x768      60.00*+  40.00     1280x720      60.00     1024x768      60.00     960x720       60.00     928x696       60.00     896x672       60.00     1024x576      60.00     960x600       60.00     960x540       60.00     800x600       60.00     840x525       60.00     864x486       60.00     700x525       60.00     800x450       60.00     640x512       60.00     700x450       60.00     640x480       60.00     720x405       60.00     684x384       60.00     640x360       60.00     512x384       60.00     512x288       60.00     480x270       60.00     400x300       60.00     432x243       60.00     320x240       60.00     360x202       60.00     320x180       60.00  HDMI-1 disconnected 1366x768+1366+0 (normal left inverted right x axis y axis) 0mm x 0mm   1366x768      60.00* 

❯ xrandr --output HDMI-1 --mode 1366x768 --right-of eDP-1

Then, in Deskreen, I selected Entire Screen and then chose Screen 2.It appeared blank but my cursor was showing and moving smoothly.I tried to use the command Shift+ Super and arrow keys to move an app (Firefox) to Screen 2. It didn't work. Then I dragged Firefox with the cursor to Screen 2.

This is how it appeared:

Ubuntu Screen

Trying to drag and move the Firefox window fully to Screen 2, it got stuck at the right on the Ubuntu screen this way:

iPad Screen

It's like having a glitch, continuously flickering. Even after closing Firefox, the issue persisted. Also, I tried with another app (e.g. nautilus) and got the same behavior. And if it is a 2nd screen, why would it appear blank in the first place? Am I misunderstanding something?

I tried with x11vnc as well:

❯ x11vnc -multiptr -repeat -clip 1366x768+1366+0

But it's giving me the same problem as obtained from Deskreen.

How to resolve this problem?