Videos can't be embedded directly into templates because email clients like Gmail, Outlook, and others don’t support the technical requirements needed to play a video within an email. Instead, you can include a preview image with a play icon to mimic the look of a video player. This allows the recipient to click and open the video in their browser to watch.
When building your template, drag and drop in the Video block. Add a YouTube or Vimeo URL and a preview image will automatically generate. You can continue to customize this video block by setting the play icon type, color, and size.