Google Home integration in OH3

  • Platform information:
    • Hardware: Raspi 3b
    • OS: Openhabian
    • openHAB version: 3.x

Hello everone,
I would like to switch my items (e.g. lamps) with my Google Home or with Alexa. I my controlling the lights vie zigbee2mqtt. Therefor exerything works fine. I added the thing in the frontend and then added channels for color, brightness and switch. Now I wanted to add a metadata to the thing in the model. If a add google metadata the thing is not shown in the Google Home app. If a add metadata to an item (e.g. brightness) it is shown in the Google Home app. If I do so a have three different “things” for one lamp in the Home App. How do I make a “complete” light recognized in the Google Home app?