Can I use PowerPoint slides in my LifterLMS lesson?

There is not a direct embed for PowerPoint in LifterLMS.

Video Demo

One option many PowerPoint users do is to record a screen share video of their PowerPoint presentation and then embed the video in the lesson. There are free options you could use to record this type of video like Zoom, or you could use a paid option like ScreenFlow.

Another option would be to do a search in a search engine and in the WordPress repository for ‘PowerPoint WordPress embed plugin’ and use one of those tools to embed a PowerPoint presentation.