Roon server is the current terminology for what used to be called Roon core. You can install Roon on another capable computer device and authorize that as your current Roon server and unauthorize your Mac. You would need to backup your old server to a USB drive and restore that to your new Roon server.
There are instructions in the Roon knowledge base and plenty of threads here.
@Robert_F shared the proper KB article above (thanks Robert! )
We’re not seeing any other devices tied to your account though, so I’d make sure you get Roon Server properly installed on the device, and then also make a fresh backup of your current database before anything else.