Actually, the latest released version of JJ2+ might actually break hosting, which is why I made a quick fix, or you could just use the Auto-Relist plus.dll I want to test.

If you haven't forwarded any ports yet, you have to forward port 10052 for both UDP and TCP. If you don't know how to forward ports, go to Portforward.com, select your router model, select any game (it doesn't matter which game), replace whatever port numbers are mentioned with port 10052 UDP and TCP.

If you did everything right, you should be able to query your own server through a GIP script by selecting your server and seeing your player's name listed.