Mo. Rev. Stat. § 28.020

The secretary of state, before entering upon the duties of his office, shall take and subscribe an oath or affirmation to support the Constitution of the United States and of this state, and to demean himself faithfully in office, which shall be endorsed upon his commission, and enter into bond, with security to be approved by the governor, to the state of Missouri, in the sum of ten thousand dollars, conditioned that he will well and truly perform the duties of secretary of state; which bond shall be attested by the governor, and deposited in the office of the governor.