Tex. Prop. Code § 41.021

If an execution is issued against a holder of an interest in land of which a homestead may be a part and the judgment debtor has not made a voluntary designation of a homestead under Section 41.005, the judgment creditor may give the judgment debtor notice to designate the homestead as defined in Section 41.002. The notice shall state that if the judgment debtor fails to designate the homestead within the time allowed by Section 41.022, the court will appoint a commissioner to make the designation at the expense of the judgment debtor.