How to add a video as a feature image in your apps
On your post/article edit screen add the following shortcode below the iframe video code. Make sure the short code looks like the image below and is not wrapped in any other formatting code. This shortcode will also suppress the video in the body so you do not have a duplicate video:
Shortcode: [unipress-video]
Here’s what your code should look like in the Text view on your page: