This server is totally incomplete.
A lot of things are missing.
To make it connect publicly, I had to use the source code of an L1 launcher to act as a proxy. When you click play, it creates a local proxy listening on the game’s port and forwarding it to the server’s IP.
My repo: https://github.com/Sage-BR/L1J4Team
If everyone uses this and applies fixes, etc., it might actually get somewhere, since the main maintainer is not active.