How attempts and grades works in Sophos Partner Portal

I am new in Sophos Products, and i have a doubt about Partner Portal. I have 4 attempts to do the exam, if i fail in all 4 attempts how it works? I have to pay for more attempts? I have a historical of all my grade i did? And if i pass in the first attempt, all exam i do next will be disregarded? or will the highest score be considered? Sorry if this is not the correct group for posting.