This config allows you to start desktop environment and enable GPU acceleration without monitor connected. Official Nvidia driver is required if you use Nvidia card. NO DUMMY DISPLAY PLUGS REQUIRED

xorg.conf

# By default, desktop environment won't start unless you connect your monitor
# This config allows you to start desktop environment and enable GPU acceleration without monitor connected. Official Nvidia driver is required if you use Nvidia card.
# NO DUMMY DISPLAY PLUGS REQUIRED
# Save the file to /etc/X11/xorg.conf
# Disable "Allow Flipping" in Nvidia settings to fix desktop flickering

# Tested on Linux Mint 21 with AnyDesk remote desktop
# GPU: NVIDIA GeForce GT 710

# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig:  version 470.161.03


Section "ServerLayout"
    Identifier     "Layout0"
    Screen      0  "Screen0"
    InputDevice    "Keyboard0" "CoreKeyboard"
    InputDevice    "Mouse0" "CorePointer"
EndSection

Section "Files"
EndSection

Section "InputDevice"

    # generated from default
    Identifier     "Mouse0"
    Driver         "mouse"
    Option         "Protocol" "auto"
    Option         "Device" "/dev/psaux"
    Option         "Emulate3Buttons" "no"
    Option         "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"

    # generated from default
    Identifier     "Keyboard0"
    Driver         "kbd"
EndSection

Section "Monitor"
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "Unknown"
    Option         "DPMS"
EndSection

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "NVIDIA GeForce GT 710"
    Option         "ConnectedMonitor" "DFP"
    Option         "UseDisplayDevice" "DFP"
    Option         "AllowEmptyInitialConfiguration" "True"
    Option         "NoPowerConnectorCheck" "True"
    Option         "ModeValidation" "NoDFPNativeResolutionCheck,NoVirtualSizeCheck,NoMaxPClkCheck,NoHorizSyncCheck,NoVertRefreshCheck,NoWidthAlignmentCheck AllowNonEdidModes"
EndSection

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "AllowEmptyInitialConfiguration" "True"
    Option         "UseDisplayDevice" "DFP"
    SubSection     "Display"
        Virtual     1920 1080
        Depth       24
    EndSubSection
EndSection