Our import tool works in most cases to apply canonical URL's to your articles pulled in from other sites. The canonicals are set at time of publish and cannot be modified in product.
If you need to correct canonical links on an existing post(s), contact us by emailing or opening a ticket on this site. You may send us your list of up to 50 posts to be modified.
Please send a consistently formatted list of your Medium URLs and their desired canonical links. Sorry, we are not able to process lists in excess of 50 items per user.