mikeg139@aol.com,
If your exam was given through Canvas Quizzes, you go into the Quiz settings and check the box that says "Let Students See Their Quiz Responses." This option is more fully explained in the Canvas Instructor Guide document: What options can I set in a quiz? in the section "Set Quiz Options."
If you are using Quizzes.Next, then the option is called "Restrict student result view" and it is explained near the bottom of this document from the Canvas Instructor Guide: How do I manage settings for an assessment in Quizzes.Next?
The Canvas Instructor Guide has a wealth of other information about Canvas as well.
