33-20-1203. Incontestability. The group life insurance policy and certificate must contain a provision that the validity of the policy may not be contested, except for nonpayment of premium, after it has been in force for 2 years from its date of issue and that a statement made by any person insured under the policy relating to the person's insurability may not be used in contesting the validity of the insurance with respect to which the statement was made after the insurance has been in force prior to the contest for a period of 2 years during the person's lifetime or unless it is contained in a written instrument signed by the person.