Go to and make sure that your desk phone's selected. If you see My Computer instead of your desk phone, select it and switch to your desk phone.
Dial a number from your app or make a Webex App call, and your call goes through your phone. Pick up your handset, use your headset, or talk over your speakerphone on your phone. Then you can continue controlling your phone from the app to put calls on hold. You can even merge and transfer calls too. You'll see everything taking place on the phone display.