MacOS VM - can I install other apps on the image?

Hi,

I installed Oracle VM on my Mac Mini, then the Home Assistant image.
It’s working fine so far.

However, I would also like to install Shinobi for streaming video from a security camera and it looks like the recommended method is on Ubuntu Server.

I think that the Home Assistant image I am using, is for Ubuntu Server, but am not completely sure.
I can’t seem to get to a standard Linux command line.
I’m pretty familiar with Ubuntu desktop.

Does anyone know which OS the downloadable Home Assistant VM image for MacOS uses?
If it is Ubuntu Server, can you point me to any documentation which explains how to install and run other software?

Thanks.