How to set Real VNC Server as default startup program - Lubuntu 19.10

I have installed Real VNC Server (Lubuntu 19.10) and can run it fine. But it does not autostart on reboot and the Options screen (where I presumably can to set it to autostart) requires sudo access. This is the message I get:

Unable to configure options for VNC Server.

This requires superuser access when running in service mode as the changes will affect all users of this system. Either you do not have a suitable method configured to gain superuser privileges (e.g. sudo), you are not authorised to do this, or you supplied invalid credentials.

I want autostart on boot as default. And be able to disable autostart as desired.

Any advice appreciated.

You need to install xterm from the repositories - this will allow VNC server to invoke sudo to give you the necessary rights.