No later than the first regular meeting of the governing body in September, or within ten days thereafter, an annual appropriation ordinance for the ensuing year must be introduced in which it shall appropriate the sums of money necessary to meet all lawful expenses and liabilities of the municipality. The ordinance shall specify the function and subfunction as prescribed by the Department of Legislative Audit for which the appropriations are made and the amount appropriated for each function and subfunction, which amount shall be appropriated from the proper fund.
(SDCL § 9-21-2)