Thanks but contacted the support and I was told that you have 1 retake per course with your subscrition.
I was hoping to retake a exam before my subscriptin expire but I was told I can't.
one retake per exam (so RHLS offers 2 retakes for two different exams).
However note that a different openshift version counts as a different exam: Eg EX180for openshift 4.6 is different than EX180 for openshift 4.10.
So practice and keep trying without fear, as Zapp Brannigan would do!