autostart a virtualbox vm on boot

[donbrew]

Evidently I am the only one.  I have Home Assistant OS in a virtualbox virtual machine.  It would be very convenient to have it start up at boot.
I have found the Application Autostart tab in Session and Startup.  The ADD button wants the startup command.

What is the command to start virtualbox and the particular VM?
Is this correct: VBoxManage startvm HAOS --type gui

HAOS is the name of the VM.

[donbrew]

I decided to give it a blind test.  It works!
Much easier to do than all of the advice from GoOgle involving making scripts and other BS.