Before or at the time of issuing refunding bonds authorized by Section 34-65 the board shall provide for the collection of a direct annual tax upon all the taxable property of the school district, sufficient to pay and discharge the principal thereof at maturity and to pay the interest thereon as it falls due. Upon the filing in the office of the county clerk of the county wherein such school district is located of a duly certified copy of any such ordinance it shall be the duty of such county clerk to extend the tax therein provided for.