Is the NUC running ROCK (Roon Optimized Core Kit)? Windows? or Linux?
Here is a summary of what ROCK is if you want to find out more about it. https://kb.roonlabs.com/ROCK:_Getting_Started
Can you hook the NUC up with an ethernet cable? This may be all you need to then access the settings through Roon,
It sounds like you may have ROCK installed on the NUC, as suggested above (thanks, @bearFNF!). Connecting your NUC with an Ethernet cable directly to the router should definitely help, and we always recommend having the Core machine connected via Ethernet. If that is not possible, you can configure ROCK using the WebUI as mentioned above.
I tried downloading the Roon applications to my MacBook, but nothing happened.
For the Mac, you’ll want to make sure you’re installing just Roon and not RoonServer. Once the NUC is connected to the network you should be able to launch Roon on the Mac and connect to the Core machine.