Which insurance company should I buy for supplementary medical insurance? How to buy?

Supplementary medical insurance is the insurance purchased by the unit for employees. Generally, they are on-the-job employees and have this treatment. General units choose life insurance companies. Because this company has a long history. Doing medical insurance is also guarding the family, starting with them. So I'm more experienced. The service is also better. First, provide personally identifiable information. Then the hospital designated by the insurance company will have a physical examination. After these procedures are completed. The company will sign an insurance contract with the insurance company. Then the unit pays the insurance premium of the insurance company every month.