What machines can I use with Apple Server. Mac mini?
Can I use a Mac Mini as a network server?
Question marked as
You absolutely can run it on a Mac mini, or any other Mac of your choosing. Most people choose the Mac mini due to its small footprint, decent price, efficient energy usage, and low system resource requirements.
The current version of the macOS Server app runs on macOS 11.3 or later per the Mac App Store listing for version 5.11.1 of the app, but you should be able to run an older version of the app on older hardware/software if you have an older Mac mini lying around.