Accessing same room (on premise Jitsi Meet server) from public and private IP

I successfully installed my first Jitsi Mett server on Ubuntu!
It’s working.
I have my server behind NAT; I can access it from
https://local_private_ip address
(inside my LAN DMZ) and from
(with a valid certificate using Let’s Encrypt)

BUT I can’t access same room from both: if I use TestRoom from local IP and TestRoom from public domain they are 2 different rooms!

How can I access same room from local ip AND from public domain?

BTW: THANK you very much for your guide! It was perfect at first try!

well, like any kind of private server out there, it’s always the same solution: you have to make the private access exactly the same as the public one using a split DNS setup, that is, the private clients address the server as “” and get the private address instead from the local DNS (or hosts files if you can’t get a DNS server to run). The public certificate is used too in this case, of course.

I put
in my
and it worked perfectly.
Thanks again