emonhub.service failed to load: No such file or directory

I tried to follow Enabling MQTT: https://github.com/emoncms/emoncms/blob/stable/docs/RaspberryPi/MQTT.md
and Installing Emonhub: https://github.com/openenergymonitor/emonhub#installing-emonhub

Since this is a Debian server (no PI) i did put emonhub into etc.

The "you must be using the emon-pi variant of emonHub for MQTT support" part is confusing.
I also don't understand if i need it because it is under an extra heading: "To enable MQTT posting from emonHub".

But its getting more confusing because i wanted to start my MQTT broker (HiveMQ) and realized i just did install a second one (mosquitto) because the port is in use.

Also what is with this topics in the tutorial? My topics look like this:
sk/base/groundfloor/bath/node2/isTemp
sk/base/garden/node5/isTemp

The documentation is really really confusing :-(