Every nonresident appointed a fiduciary in this state, before entering upon the duties of the trust, shall appoint in writing an agent residing in the county where the appointment is made. By such writing, the nonresident fiduciary consents that the service of any notice or process upon such agent shall have the same force and effect as personal service upon the fiduciary within such county and state. Such writing shall state the correct address of such agent and shall be filed in the district court where such appointment is made. Such writing shall include written acceptance of such appointment by the designated agent. Service of notice or process upon such agent shall have the same force and effect as personal service upon the fiduciary.