Can't see my Homematic window contact as a thing

  • Platform information:
    • Hardware: PI 3
    • OS: openhabian
    • Java Runtime Environment:
    • openHAB version: with openhab 3.2.0

I have a CUL USB stick CC1101 from Busware. I try to integrate with this device a Homematic HM-Sec-SCo window contact. For that I have installed the latest Homegear installation ( Version: 0.7.50-3478). With this I was successful to pair my contact with the Homegear server. Now I’m struggling to have this device as a thing in openHAB. In some other threads I read, that I need to install the Homematic binding and just go to the inbox. I did install the Homematic binding, but neither I can find a inbox, nor does anything pop-up at the thing window, as my roomba robot did for instance. Has anyone an idea, how I can make the connection, or what I’m doing wrong?