Hello David,
We prepared a documentation for you about how to add video on post. You have to add video from external source like Youtube with video ID. Please follow the documentation and know about how to add the video. Hope this documentation will help you. https://doc.acmethemes.com/supermagpro/#HowtoaddVideoonplaceonFeaturedImage?
If you still fell confusion, feel free to ask. We will provide the best method for you to integrate video on post.
Best Regards,
Acme Supports