If you ever need to edit, update or change the URL for a canvas, you can do it through your dashboard.
Changing the canvas URL doesn't just change the base URL (e.g. staging.website.com -> website.com). It can also change the URL path of that canvas (e.g. /about-testing-page -> /about).
You don't have to create a new canvas if the domain changes!
If the URL structure is the same and only the base URL has changed, previous comments will carry over when you edit the URL and your comments will continue to be visible on that canvas.