The amount of group life insurance or group accidental death and dismemberment insurance covering a retiree, dependent, surviving spouse, or surviving dependent child on the date of death shall be paid, on the establishment of a valid claim, only to:
(1) the beneficiary designated by the person in a signed and witnessed document received before death in the office of the trustee; or
(2) a person in the order prescribed by Section 824.103(b), Government Code, if a beneficiary is not properly designated or a beneficiary does not exist.