Mo. Rev. Stat. § 488.1010

A will may be deposited by the person making it, or by some person for him, with the probate division of any circuit court, to be safely kept until delivered or disposed of as hereinafter provided. The clerk of the court, on being paid a fee in an amount determined pursuant to sections 488.010 to 488.020 *, shall receive and keep, and give a certificate of deposit for, a will deposited with the court pursuant to section 474.510.