Hi Theodore John,
For a limited period, Mendix is offering free certifications for everyone! This period lasts until the end of May. If you don’t pass the exam the first time, you have another free attempt. There is no waiting period between these two attempts, but there is only one retake. If you fail both times, you will need to pay for a new voucher to do the exam.
Please check the frequently asked questions on this page:
Best of luck!