Installing loomio - Searching for a good begining

I would like to install loomio in a VPS, with Debian and NGINX. It's being hard for me to find an starting point, basic documentation such as installing steps. I have found kind of an installation guide but it deals with docker/ubuntu server installation. I would like to find something like this (for moodle) or this (for mantisBT), with which I can choose which OS and webserver to use. Is there anything similar for loomio? And if not, where should I start to build a loomio server based on Debian/NGINX, without docker?