1. In the 3CX app, click on the two cogs icon at the bottom right
  2. Click into the "Audio Options"
  3. In each of the dropdowns, there should be the option of your headset speaker or microphone, select the option for your headset
  4. Once all three are set, click the OK button and then the left pointing arrow at the bottom
  5. The app is now configured to use the connected headset for incoming and outgoing calls