Click on the meeting you wish to attend - either from the "On Air" ticker or from the video meeting schedule. When the meeting main video feed is fully loaded, click on "Turn Cam On" and then you will see your own video feed in the small box left from the green buttons. When that is fully loaded, the "processing" button will turn into a "Request to Share" button. Clicking on that will put you in the upper right hand box. You are now visible to the audience and the chairperson and will be selected to share when it is your time to share.