Because only the municipal (district) county-level administrative health bureau (epidemic prevention station or CDC) has the right to apply for a health certificate.
Other departments, institutions and hospitals have no right to handle it. Even if they do, it is invalid and cannot be checked.
(At most, it is supported by the company internally, and cannot be checked externally)
Because from April this year 1, it will be free to apply for a health certificate at an epidemic prevention station or CDC.