Dedicated server currently only runs on WIndows, due to the console API. Contact Bryan on the discord if you'd like to run on Linux and I'll get support running for you.
To install or update the dedicated server you can download the SteamCMD command line version of steam from https://steamcdn-a.akamaihd.net/client/installer/steamcmd.zip See https://developer.valvesoftware.com/wiki/SteamCMD for full details on SteamCMD.
Then run this command to instal or update the game
steamcmd +login yourusername +force_install_dir C:\NSTP +app_update 711810 validate +quitOnce installed run the "Dedicated Server.bat" file to start a dedicated server.
The ports can be set via the -port command. Defaut is ports 1701-1703 UDP. These will need to be opened on your firewall and port forwarded on your router if you are behind one.