The game will pop a debug terminal, that will forward your commands directly to the in-game source console backend. SQVM prints are also enabled, and the hooks will attempt to load game vscripts out of `platform\` relative from the game executable before falling back to the SearchPath's defined in GameInfo.txt or the in-memory VPK structures.
People can join with that over the "Private Servers" button. If you do that your IP will still be stored on the database till you stop hosting the server to ensure people can connect.
Alternative way is just to host the server without ticking the server browser checkbox and just give the people you want to connect the IP including the port.
TL;DR If you tick the server browser box in "Host Server" your ip will be stored till you close the server.