The Helfertool should run on most current Linux distributions, but is mostly used on Debian at the moment.
The most easy way to deploy the Helfertool is using Docker and the helfertoolctl package which is available for Debian and CentOS. Of course, you can also use the Docker container on other systems, but the helfertoolctl package provides a wrapper script around Docker and useful things like a systemd service file. Beside that, it is also possible to deploy the Helfertool manually as a usual Django application.
To deploy the Helfertool to an own server, a few dependencies are necessary:
Database: PostgreSQL (recommended), MySQL, MariaDB or SQLite
Reverse proxy: nginx (recommended), Apache or other suitable software
Mail server to send out mails
The following documentation only explains the setup on Debian with Docker and helfertoolctl in detail. For CentOS, see in the helfertoolctl section for the repository and follow the Debian documentation.
Please feel free to submit corrections and additions.