Hey Carsten,
setting up and working with MQTT is out of the scope of the daemon documentation but you should find everything you need to first make sure MQTT is up and running here:
@curlyel happy you got it working right away. The battery information would certainly be something we can add. Please create a GitHub issue! The battery use is something I never looked at closely but I’ve been polling my sensors at home for quite some time now and they report 90-something percent. I wonder if those readings are correct. @skatun do you know more?
Regarding signal quality: Please check the output of sudo systemctl status miflora.service, also there is the idea to enhance this: Use systemd status for a summary · Issue #16 · ThomDietrich/miflora-mqtt-daemon · GitHub