When referring to files within CANVAS from tools installed within your CANVAS classroom, follow the steps below to format the URL appropriately.
Step 1
Copy the URL of the file you wish to link.
Find the item within the Files area of your classroom, right-click the link, and "Copy Link Address"

Step 2
Paste the link address into an editor or document and replace ?preview= with /
EXAMPLE:
https://canvas.harvard.edu/courses/160033/files?preview=23184991
is adjusted to
https://canvas.harvard.edu/courses/160033/files/23184991
Step 3
Copy the new link and use it within the 3rd-Party tool where needed.
Email: dce_instructionaltechnology@fas.harvard.edu Support for students is provided by Academic TechnologyInstructor support
Web: teach.dce.harvard.edu/itg
Emergencies: call the help desk at (617) 998-8571Student support
Email: AcademicTechnology@dce.Harvard.edu
Phone: (617) 998-8571
Resources: Canvas Student Support Guides & Tips