I have installed MaxLabs Grader already. I registered with my school email. I registered under the developer edition.
When I search for MaxLab Grader it does not appear in my applauncer or in my search bar. Only a Max Lab Grader information report is present.
MaxLab Grader is not present in my AppLauncher
That was the problem! After I changed to Lightning Experience everything was resolved. Thank you for the help.