Each person who tests milk from permitted producers shall obtain a license to test. Application for a license shall be made to the director. The license fee provided for in KRS 260.815 shall accompany the application. All applicants shall demonstrate their proficiency in testing by satisfactorily passing an examination prescribed by the director. Prior to taking an examination for a license, an applicant shall obtain a temporary license. Each licensee shall notify the director, in writing, within thirty (30) days of a change of address.