So my friend connect to my server via hamaci can anyone help me with htis issue?

Besicaly me and a friend wanted to make a teamspeak server with the help of hamaci becuse 1. I am to poor ot rent a server and 2. I dont wanna leek my private IP to people we wanna play with, but when we tried to use it he couldnt connect, does anyone know why?

Please rent a server when the only reason is to hide your IP from others.

UDP traffic must be possible and these ports must be opened