Each user is able to synchronize a PowerPoint presentation during their speech similar to what happens during a real event. After the PowerPoint presentation has been sent to all users (see how to sent a file) and ensure that the file has been received correctly by all participants in the meeting, you can synchronize all participants in the meeting during the speech with the selected slide in the Documents window by pressing the Synchronize PowerPoint button on the toolbar or through the horizontal menu: Documents à Synchronize the PowerPoint slide.

Each time you press the button the PowerPoint presentation will automatically place all users on the slide chosen by the speaker.
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Solving a problem related to synchronizing
Power Point