Usually, regular or relatively good British universities do not make-up exams, except in special circumstances, such as illness or family changes, but this needs to be proved.

Therefore, if you fail the exam or thesis, you can only retake the exam.

If your school can make up the exam, but you don't take it, your report card will show that you failed the first time, and then make up the exam. Basically, the employer or HR just brushed off your resume without thinking about it. Universities that can make-up exams are basically garbage or diploma workshops.

Therefore, I would rather retake the exam and get a high score. When you submit your resume after graduation, you can note at the back: because of XXX, I didn't hand in my paper last semester, and the school is not allowed to retake the exam.

Do you understand what I mean?

Write so much, take it.