Every corporation organized under this article shall procure from the Commissioner of Insurance a certificate of authority to do business, for which the corporation shall pay the sum of two hundred dollars ($200), and the certificates of authority shall be renewed thereafter on or before the first day of March of each year. The corporation may then enter into contracts with the public, subject to the restrictions contained in this article, for benefits under its health service plan. It shall be the duty of the corporation to enter into contracts with and issue certificates to those of the public who may desire to avail themselves of the benefits of the health service plan and who, under its rules and regulations, make application and are eligible therefor. The contracts may provide for more than one class of services or benefits, may designate the person or persons, or the class of persons, entitled thereto, may designate the health care facilities and providers which render the services provided for, and may specify the charge or dues required to be paid for the services or benefits. No corporation shall issue or sell any contract until the form of the same has been filed with the Commissioner of Insurance.