Skype for Business

I am trying to present a training and throughout the trial calls I have been unable to upload a powerpoint with an embedded video.  I have tried to upload the saved video file as well as the embedded youtube video.  Neither have been successful.  The file has been compressed and optimized.  Final compressed size is 56 MB.  It is not my program, I join the call and the person who created the call makes me the presenter.  I am able to share my screen so they can see the video but there is no audio, if there was audio for the attendees, I would not even need to upload the video. 

Is there anyway to know how to get audio on the other side?  and if not, why I am unable to upload the video or PPT file with the video embedded?