Is it legal for the unit to let employees wait for their posts to apply for health certificates?

According to relevant information: legal, this is a reasonable requirement. The unit can require employees to have health certificates, otherwise they can't take up their posts, so it is legal for the unit to require you to apply for health certificates. However, the unit arbitrarily decided to wait for employees. If the employee disagrees, the employee can refuse to accept it and ask to continue to perform the original labor contract.