Section 22. Every insured person shall give written or printed notice to every person with whom he is about to enter into a contract of hire that he has provided for payment to injured employees by the insurer or by means of self-insurance as provided in this chapter. An employer ceasing to be insured by an insurance company shall, on or before the day on which his policy expires, give written or printed notice thereof to all persons under contract with him. In case of the renewal of the policy no notice shall be required. He shall file a copy of said notice with the department. The notices required by this and the preceding section may be given in the manner therein provided or in such other manner as may be approved by the department.