How to build CalDAV Server – change IP

I try to build a CalDAV Server on my server with Ubuntu 18.04.1 LTS. I have a real IP (configured in Ubuntu) but I don’t no how to configure the CalDAV Server.

I was following this instructions but i don’t know how to change my IP localhost to real IP to be able to use it in Mozilla Thunderbird Lightning (Windows).

Could you share with me step by step to create the CalDAV Server using Radicale.

Thank You!