Unable to use the nvidia-settings to select the Titan V.

I have already installed the nvidia-driver-410 via ppa. The nvidia-smi can show the information of the GPU.
But the nvidia-settings does not work. It shows that.

ERROR: Unable to load info from any available system

And I use the command nvdia-xconfig. It shows that.

good@AirSim:~$ sudo nvidia-xconfig
[sudo] password for good: 

WARNING: Unable to locate/open X configuration file.

Package xorg-server was not found in the pkg-config search path.
Perhaps you should add the directory containing `xorg-server.pc'
to the PKG_CONFIG_PATH environment variable
No package 'xorg-server' found
New X configuration file written to '/etc/X11/xorg.conf'

Here is my bug report.

Please check using this as /etc/X11/xorg.conf

Section "Device"
    Identifier     "nvidia"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BusID          "PCI:2:0:0"
    Option         "AllowEmptyInitialConfiguration"

I have changed xorg.conf like above and reboot. However, after I type the password, the Ubuntu login interface get stuck.
Here is my bug report.

Your monitor is still connected to the onboard graphics. Connect it to an output on the nvidia card.

Thank you!!! When I connect my monitor on the Titan V, nvidia-settings works!
Thank you!!!