Step 1: Click the “Design” step.
Step 2: Click the “Edit Card” section.
Step 3: Click the “Add Video" button.
Step 4a: Drag and drop a video file or click "Choose your video to upload."
Step 4b: Embed a video from Vimeo, YouTube or Giphy
*NOTE* If uploading your own video, it must be an AVI, MP4 or MOV file under 400mb.