If the local policy allows, and your health code contains your personal information, and it has just been printed and is time-sensitive, you can use it. However, if your health code was printed a long time ago, it is not timely and misleading, so you can't use it.
The health code is based on the actual real data, which can be generated by citizens or people who have returned to work on their own online declaration and background audit. As an individual entering and leaving electronic certificate locally, the QR code can be declared once, which is universal in the whole city. The introduction of the health code aims to make the work of returning to work more accurate, scientific and orderly.