1. Go to your course in open edX Studio e.g. https://studio.<your-subdomain>.skillsnetwork.site or https://studio.<portal-subdomain>.<your-domain>.com
2. Go to Settings > Advanced Settings > Advanced Modules List, add "redoexam" (values are comma-separated). Click 'Save Changes' at the bottom of the screen.
3. Go to Content > Outline
4. Under 'Final Exam', add a new subsection, called "Retake Exam" or something similar. In this subsection, create a new unit.
5. Within the new unit, in the 'Add New Component' menu, select Advanced > redoexam.
Click on Edit to customize the redoexam component.
Maximum number of attempts: determines the total number of times a user can take the exam. By default, it is set to 3, allowing each user to retake the exam twice.
Time between attempts: determines how many hours a user must wait after attempting the exam before they are able to retake it. By default, it is set to 24, allowing each user to retake the course's exam one day after their previous attempt.
Don't forget to PUBLISH your changes.