Is the call back option not supported in WebEx Events when using Edge Audio? I see the option available for Toll & Toll Free audio but option is gone when Edge Audio is configured.
It is not supported for events. From the Edge audio guide:
"Extension callback for Edge Audio allows users to join Webex meetings using the Call Me feature and their internal extension. This is only available for Webex Meetings, and doesn't work with Webex Events, Webex Training, or Webex Support."