The group life insurance policy must contain a provision that any sum becoming due by reason of the death of the person insured shall be payable to the beneficiary designated by the person insured, subject to the provisions of the policy if there is no designated beneficiary as to all or a part of the sum living at the death of the person insured, and subject to any right reserved by the insurer in the policy and set out in the certificate to pay at its option a part of the sum not exceeding $4,000 to any person appearing to the insurer to be equitably entitled to it by reason of having incurred funeral or other expenses incident to the last illness or death of the person insured.