Help with IP errors and disconnect

[pedroevil51 1]

Well, I started messing with Metin2 very soon, so I have little experience with the subject. I created a server and wanted to have fun with a friend so we could play.
I created without hamachi because the pc of some friends does not get along very well with the program.

I tried editing the / CONFIG
with BIND_IP: 192.168.15.XX (My local ip)
but no one could get in, so they selected the character and took a disconnect back to server selection

I tried to put my public IP, my no-ip, etc ... but all these give socket error

If someone can help me, I would appreciate it very much, I am very happy to have entered the community and I am willing to spend some time dedicating myself to improving