How to Have YouTube Video Embeds for Post Thumbnails Instead of Image Uploads?

I want to try making my blog post thumbnails into YouTube video embeds, sort of like in this video.

However, I don’t see any Format option for posts as shown in this video, and what I’ve read suggests that a missing Format option is due to the theme.

Any tips/ideas on how to customize the thumbnails of posts would be appreciated.

I want to cut down on how many images I will be uploading to my website media over time by relying more on embedding than uploading image after image, essentially.

You simply build it from scratch using the query loop feature… no need to use the posts element. Plus, to render the video as a thumb you will need to go with custom fields–use either Pods or ACF…