How to Install Jitsi with TLS to work with My Moodle Server

I am going to set up a Digitalocean Droplet to run Jitsi and integrate it with my Moodle Server Droplet (which already has a cert from Lets Encrypt). In reviewing your tutorial, it shows I have the option to use either the Droplet IP Address or register a Domain Name (which I do not want to do) but if I use only the IP Address then I will not get the TLS cert.

Since I want the video conferencing sessions of my Moodle users to be secure, how should I follow the tutorial to get the Jitsi server up and running?