Okla. Stat. tit. 6, § 6-1009
Official's oath or affidavit
In any case in which the laws of a state require that a
corporation acting as trustee, executor, administrator, or in any
capacity specified in this article shall take an oath or make an
affidavit, the president, vice-president, cashier, or trust officer
of such bank or trust company may take the necessary oath or execute
the necessary affidavit.