This certification is issued by the Taxi Services Commission and is required in order to legally drive any commercial passenger vehicle within Victoria (including buses, taxis, and Ubers)
Apply here for the accreditation to drive a commercial passenger vehicle and private bus
As you will see, this application requires medical clearance. For most applicants, this is a straightforward but somewhat time-consuming process. The medical clearance simply involves a visit to your GP to check on such things as blood pressure, eyesight etc. Essentially, they are checking to make sure applicants are not likely candidates for a stroke or heart attack at the wheel.
Page 13 of the application form also requires you to consent to the TSC undertaking a criminal record and driving record check through Victoria Police and VicRoads.