Okla. Stat. tit. 11 § 15-102
The procedure in municipalities which do not provide by ordinance or charter for the manner of exercising the initiative and referendum powers shall be governed by the Oklahoma Constitution and general state law, except as otherwise provided in Sections 15-101 through 15-110 of this title. The duties required of the Governor by state law shall be performed by the mayor; the duties of the Secretary of State shall be performed by the municipal clerk; and the duties of the Attorney General shall be performed by the attorney for the municipality. The procedure for initiative and referendum as to municipal legislation shall be as nearly as practicable the same as those for measures relating to the people of the state at large.
Okla. Stat. tit. 11, § 15-102