Microsoft Certification Exam 70-778: Analyzing and Visualizing Data with Power BI

Hello Power BI community I am interested in taking the 778 Exam, is it an online exam or do you need to go to a certain location?
I have made some research and found the preparation books in Amazon (paper and online) but are there also training related to this exam? is there another exam that should be taken prior to this one? Any advice would be good, thanks!