Mo. Rev. Stat. § 474.550

At the time of its execution or at any subsequent date, an electronic will may be made self-proved in the same manner as specified in section 474.337 or, if fewer than two witnesses are physically present in the same location as the testator at the time of such acknowledgments, before a remote online notary authorized to perform a remote online notarization in this state under the law of any state or the United States, and evidenced by a remote online notarial certificate, in form and content substantially as follows, subject to the additional requirements under section 486.1165: