Unless otherwise provided, such applicant for any license under this Title shall at all times maintain in full force and effect a policy of property damage and public liability insurance equal to the minimum state requirement for private vehicles on any vehicle used by said applicant, his servants, agents, or employees in the conduct of the business or thing licensed. A copy of such policy shall be filed with the Auditor with written endorsements thereon showing that the Auditor must be given written notice in the event of cancellation of said policy either by the company or the insured.