It appears that the Story Map Series only allows an iframe for inserting videos. Although, I cannot use YouTube or other hosting services so the link is directly to the video instead of a video host. I would like to simply embed HTML5 instead, which I attempted below.
First I created the html file containing this:
<video controls="controls"> <source src="url_to_my_video.mp4" type="video/mp4"> </video>
Then I included the following iframe in the story map.
<iframe src="url_to_my_file.html" />
The video never appeared. Any ideas?