Updating new user server info?

Hi,

Just started using this today - amazing.

However, trying to add a few new users and the email contains the server local IP address - can this be changed so it can show my external address?

It is running on a new Ubuntu VM installed via snap so totally clean and is running behind my firewall.

It shows to connect to http://192.168.1.234/blah blah blah for example when I would like to show a normal www.123.com type address.

I've looked in the Admin section so I assume it need to doing something command line based?

If anyone has any ideas that would be great!