Configure collabora docker installation on Debian10 to use with nextcloud

The main task is to make reacheble from Nextcloud installation a Collabora docker installation on Debian10 vps from internet in order to use it for Online editing; If it will work, we would need to have then some "step by step of "how to" in order to keep it working. At this moment, an url that should give collabora access for nextcloud return appache default web server page. It is also corresponding Let's Encrrypt ssl certificate installed.