Each firm in the business of installing, altering, inspecting, repairing, recharging, servicing, maintaining, or testing fire suppression systems or in the business of inspecting, repairing, recharging, servicing, maintaining, or testing portable fire extinguishers is required to obtain a license from the Commissioner. The annual fee for said license shall be as established by the Commissioner by rule or regulation, but such license fee shall not exceed $50.00.