This article provides two methods of embedding a narrated PowerPoint in Moodle:
Method #1: Save the narrated PowerPoint as an MP4 video file
Using PowerPoint 2013 or newer, you can save your narrated PowerPoint as an MP4 video file and embed it in Moodle using My Media.
Steps
Open your narrated presentation in PowerPoint 2013 or newer.
Select File
Select Save-As
Select a location to save the file
Set the Save as type to MPEG-4 Video (*.mp4) and select the Save button
The narrated PowerPoint might take a while to save, depending on how much narration is in the PowerPoint and the speed of your computer. A progress bar will appear at the bottom.