If any authority is created by the governing body of a municipality which has established a municipal retirement system pursuant to Chapter 451, Acts of the 72nd Legislature, Regular Session, 1991 (Article 6243n, Vernon’s Texas Civil Statutes), then the board of such authority shall have the authority to provide and shall provide retirement benefits for employees of the authority by participating in and making all contributions required or authorized by the municipal retirement system established by the municipality pursuant to Chapter 451, Acts of the 72nd Legislature, Regular Session, 1991 (Article 6243n, Vernon’s Texas Civil Statutes).