@MoatazKhan12 and @FrankieJones11 ...
You would need to temporarily re-enroll your students back into the course, and those grades/results from the quiz should re-appear so that you can review the results for your needs. One additional thing you might be able to do is keep the student enrolled in the course but set him/her as deactivated. If you are not able to deactivate a student on your own as an instructor, you would need to reach out to your school's Canvas administrator or someone from your school's Online Learning / eLearning / Distance Education department to help you with this. Here is a Guide that has more information for you:
How do I deactivate an enrollment in a course?
Hopefully this will help a bit. Sing out if you have any other questions...thanks!