How to assign slide control
- Begin sharing a PowerPoint, or Google Slides or other type of presentation.
- On the sharing toolbar, click Slide Control Note: This option will only be available when you are in presentation mode. Note: This option will only be available when you are in presentation mode.
- Select one or more participants you wish to give slide control.The slide control button will update with the number of participants with slide control next to the icon.
After you’ve
                        assigned slide control to
                        a participant, they will
                        retain slide control as
                        long as you continue
                        sharing. The slide
                        controls will disappear if
                        you exit presentation
                        mode, but they will
                        re-appear when you begin
                        presenting again. 
How to use slide control
When you’ve been
                        given access to slide
                        control and the presenter
                        enters presentation mode,
                        a banner notification will
                        appear, informing you of
                        the new access. The slide
                        controls will appear just
                        below the banner, in the
                        bottom-left corner of the
                        presentation
                        view.
- Click the left arrow and right arrow buttons to
            move the presentation backwards or
            forwards.
- Alternatively, you can use the left
            and right buttons on your keyboard to
            move the presentation backwards or
            forwards.