For proctored exams, you have the option to purchase an Exam Retake license if you fail the exam.

There is one retake exam included with each unproctored exam, so if you fail the exam the first time, you can retake it. If you fail the exam a second time, you will need an Exam Retake license to retake the exam.

If you are a self-pay student, you can purchase the license by yourself. If you take the course through an organization or your teacher, then your organization or teacher have to buy the license and then assign it to you.