Okla. Stat. tit. 21, § 352

It shall be unlawful for any state officer or deputy or employee of said officer to issue, cause to be issued or consent to the issuing, or to pay, cause to be paid or consent to the paying of any state warrant, order, or other evidence of public debt in excess of the appropriation duly made or when no appropriation has been made by the Legislature, for the fund upon which the same may be drawn.