Same changes at new installation

I changed something in my self-hosted server and I want to run jitsi on another server with the same configuration that I changed. How can I do it?

If you mean to copy the whole installation over to another machine, here is what to have in mind:

Jitsi Meet uses the domain name (FQDN you entered during the install) internally in a lot of places.
In the new install you should change the occurrences of the old FQDN with the new one - they are in /etc/jitsi/* /etc/nginx/* /etc/prosody/* /var/lib/prosody/* (also take a look at the subfolder names and ssl files there), eventually also /etc/turnserver.conf…
You have to create a new self-signed SSL on the new server or if you used LetsEncrypt - issue a new LE SSL for the new DNS name there.

The DNS name is also in debconf, this will be important for upgrades. you can check with:

debconf-show jitsi-meet-web-config
debconf-show jitsi-videobridge2

There are two parameters there - “jitsi-meet/jvb-hostname” and “jitsi-videobridge/jvb-hostname
In order to change them to the new hostname, use “debconf-set-selections” command:

echo "jitsi-meet-web-config jitsi-meet/jvb-hostname string New-DNS-Name" | debconf-set-selections
echo "jitsi-meet-web-config jitsi-videobridge/jvb-hostname string New-DNS-Name" | debconf-set-selections
echo "jitsi-videobridge2 jitsi-videobridge/jvb-hostname string New-DNS-Name" | debconf-set-selections

NB: If the changes you made are not major and you can recreate them, it’s easier to just install the new server from scratch and apply them there.