During the installation you'll be asked to enter the hostname of the Jitsi Meet instance. If you have a FQDN hostname for the instance already set ip in DNS, enter it there. If you don't have a resolvable hostname, you can enter the IP address of the machine (if it is static or doesn't change).
This hostname (ot IP address) will be used for virtualhost configuration inside the Jitsi Meet and also you and your correspondents will be using it to access the web conferences.
This hostname (or IP address) will be used for virtualhost configuration inside the Jitsi Meet and also you and your correspondents will be using it to access the web conferences.