I'm going to assume you are asking as an attendee in an event. The Webex Meet app is being phased out and is no longer needed as a separate app to join meetings. After making sure you have the most recent version of the Webex app, open the app and click on "Join Meeting." The "Join Meeting" option won't be available until 5 minutes before the scheduled start time.
Please reply back if you weren't asking as an attendee or if you have any other questions.
