As studying intensely while working full time is challenging, and may cause a temporary decrease in your work performance, you very much need your boss to advocate for your examination within the company.
Exclude conflict of interest
If there is a conflict of interest, meaning your boss does not recognize any value and is against you taking the exam, there is probably no point in trying to convince him/her. In that case you usually have two choices: either you try to take the exam anyway and keep it as a secret, or you don’t take it while working and consider taking time off or switching to another job, depending how important the exam is for you and your future development. Read more