The video can be added to the Description of the Event Registration.
  1. Go to Core > Events > Registration Forms 
  2. Approval
  3. Event Registration
  4. Edit
  5. General Info tab
  6. Scroll down to the Description text area

To add a link to the video:
  1. Navigate to onMessage.
  2. Select Content Types > Video
    • If your school does not use onMessage, or if you are not a Page Manager, you can access content through Core > Communication > Content Types.
  3. Upload the video to a video category.
  4. Click the URL button to the right of the video in the category.
  5. Edit the event registration through onMessage.
  6. Hyperlink text in the description to the video URL.

To embed through HTML:

<iframe width="560" height="315" src="VideoURL" frameborder="0" allowfullscreen></iframe>
The "VideoURL" will be the URL you get from the Video Content Category.

If you're using an external video from a site such as YouTube, you can click "Share" then "Embed" and take the iframe code provided here, and this will be your embed code you place in the HTML.