NetCoreServer is 3rd party library not supported by this forum. That said the site has examples.
https://chronoxor.github.io/NetCoreServer/
a quick review of the source code shows that it just uses System.Net and System.Net.Sockets under the covers. also the repo does not have very active updates (last update 12/8/2023). if you pick this repo, I recommend you fork it first, so you can apply fixes you need.