If you would prefer to embed your course trailer onto your Canvas site, rather than directly uploading it, here is a step by step of how to do that. As well, here is a video that walks you through this.
Click on "Edit" icon
Click on Youtube widget
Paste in the URL link of your video
Click "Embed" icon and then "Update Syllabus"
Click on "Edit" icon
Click on "HTML Editor"
Copy embed code from "Share" tab on Vimeo
Paste embed code into HTML Editor, and click "Update Syllabus"