There is no difference between installing software on a VM and on “bare metal”. The OS takes care of the hardware stuff.

I installed it according to their manual on their website (https://radicale.org/v3.html) which is imo pretty easy. The TLDR is that you first install python3 and its package manager pipx, then you install radicale using pipx and finally you run it as a systemd service. You can just copy their service template. The issue comes when you need to run multiple web services though. Radicale wants to be on the website root (website.com/ instead of website.com/some/path/blablabla/ ) which is not as trivial to set up as the previous steps. They have a template for nginx and apache but you need to kinda know the very basics of one of these to set it up.

Also on debian there is a package so you could technically just apt install radicale and then systemctl enable radicale if you want to avoid creating a service and installing python.

Obviously you need to create a basic config either way according to their manual. At least for password authentification.

The point is that they have recently focused on better binary package availability. Sure they always had support for binary packages but most software needed to be compiled.