install and configure x11vnc on ubuntu server 18.04 LTS

sudo apt-get install x11vnc

x11vnc -storepasswd 

Enter VNC password: *********
Verify password: *********  
Write password to /home/rahul/.vnc/passwd?  [y]/n y
Password written to: /home/rahul/.vnc/passwd

sudo x11vnc -auth guess -forever -loop -noxdamage -repeat -rfbauth /home/rahul/.vnc/passwd -rfbport 5900 -shared

script auto start

1. make file x11vnc.service in /etc/systemd/system :
sudo mcedit /etc/systemd/system/x11vnc.service (mcedit – my prefered editor , i’m sorry for vi :)))

with text (change RAHUL for you name):

[Unit]
Description=x11vnc remote desktop server
After=multi-user.target

[Service]
Type=simple
ExecStart=/usr/bin/x11vnc -auth guess -forever -loop -noxdamage -repeat -rfbauth /home/RAHUL/.vnc/passwd -rfbport 5900 -shared

Restart=on-failure

[Install]
WantedBy=multi-user.target

2. sudo systemctl daemon-reload
sudo systemctl start x11vnc
sudo systemctl status x11vnc

3. if it’s worked
sudo systemctl enable x11vnc.service

Ref: setup-x11vnc-server-on-ubuntu-linuxmint