There are 2 options for locating permalinks in ProQuest. Both already include the library's proxy prefix, so, all you need to do is copy the document URL in the indexing details section of an abstract or from the "cite" link and you're set to go.
Option 1: Click Cite. Then, locate Retrieved from. Copy the link that appears after Retrieved from. Paste the link into Canvas.
Option 2: Or use the document URL (highlighted below) found in the Indexing Details section located at the end of an abstract.