A extensively description in german can be found at http://wiki.nelson-it.ch.
To install the ERP on ubuntu or Debian/Raspian add the PPA
| Linux | PPA | Version |
|---|---|---|
| Ubuntu 22.04 LTS | http://ppa.nelson-it.ch/ubuntu jammy main | actual release |
to the /etc/apt/source.list
and download nelson-ppa.gpg (sourceforge.net) to /etc/apt/trusted.gpg.d.
Then select the package mnesbs for installing.