Including Sensors for Gas and Water in Homeassistant

I just can’t get any further. Probably a beginner’s mistake. I have MQTT installed and would like to display the values ​​read from my Smart-Maic as a sensor. I managed to get the connection and the data is also read out (here from the MQTT Explorer):

grafik824×255 4.81 KB

How do I get this into the Configuration.yaml?
I tried this here. But something seems to be missing because the sensor appears, but no values.

mqtt:

sensor:
name: “gas meter”
state_topic: “1761610240.TCh1”
unit_of_measurement: “m³”
icon: “mid:fire”

And no entities are displayed in my MQTT Broaker.

In the settings under Entities it does, but without values.

Can anyone help me here? I would be happy.
Greetings Sebastian