You can start a call on your Webex device by using the Cisco Webex app.
You can use the Webex app to place calls on a Webex device when your app is connected to it.
Call a space: When calling a space, all participants in that space are notified on their devices. During the call, anyone in that space can join by selecting the green Join button.
Select a space, and click the Meet icon.
Call a contact: Select a contact and click on the video call icon. Choose Webex Call.