can't create fake display when using modesetting

I want a fake display in my ubuntu20.4 to use ipad as a second screen.
There are two graphic cards in the laptop.
Code:$ lspci | grep VGA
>> 00:02.0 VGA compatible controller: Intel Corporation UHD Graphics (rev 05)
>> 01:00.0 VGA compatible controller: NVIDIA Corporation Device 1f95 (rev a1)I have enabled Nvidia prime in NVIDIA on-demand mode.

The /etc/X11/xorg.conf file looks like this

Code:section "Device"
Identifier "intel"
Driver "modesetting"
BusID "PCI:0:2:0"
EndSectionAnd I added 20-intel.conf in /usr/share/X11/xorg.conf.d/ with following contents.

Code:Section "Device"
Identifier "intelgpu0"
Driver "intel"
Option "VirtualHeads" "2"
Option "TearFree" "true"
EndSectionAfter rebooting I ran the following commands

Code:xrandr --addmode VIRTUAL1 1920x1080
xrandr --output VIRTUAL1 --mode 1920x1080 --left-of eDP1After that I was able to create virtual display and use ipad as my second screen. But the graphics was fuzzy & videos in vlc wouldn't play or started lagging.

After changing the driver to modesetting in 20-intel.conf

Code:Section "Device"
Identifier "intelgpu0"
Driver "modesetting"
Option "VirtualHeads" "2"
Option "TearFree" "true"
EndSectionThe fuzzy graphics issue was solved. But I can't create the virtual display using the above xrandr commands I get the following error

Code:xrandr: Configure crtc 3 failed.