When you click on Moderate, click on the hyperlinked student name. There you can click on the hyperlinked "Log" to view the student's actions during the quiz. There you can view the student's attempt and also permit extra attempts.
From the Moderate page, you can give a student an extra attempt by clicking on the pencil next to their name.
If you can't see any of these things, then check your name under "People" to be sure you are classified as a "Teacher" in the Canvas course. If you still can't do anything, then definitely submit a help ticket because something is very wrong!
Best wishes.
This discussion post is outdated and has been archived. Please use the Community question forums and official documentation for the most current and accurate information.