Hi Daniel,
Welcome to the openHAB community 
. Which OH2 version do you use? 2.4? Or lower? For the discovery of Hue devices the “type”: “ZGPSwitch” is important. IIRC support for it has been added long time ago (see [hue] Added support for Hue Tap Switch by cweitkamp · Pull Request #6744 · eclipse-archived/smarthome · GitHub). I am wondering why it is not found in your setup.
May I ask you to put the JSON into code fences? Thanks.