There shall be a provision that no statement made by the applicant for insurance shall avoid the insurance or reduce benefits thereunder unless contained in the written application signed by the applicant; and a provision that no agent has authority to change the policy or to waive any of its provisions; and that no change in the policy shall be valid unless approved by an officer of the insurer and evidenced by indorsement on the policy, or by amendment to the policy signed by the policyholder and the insurer.   [PL 1969, c. 132, §1 (NEW).]