If you are 18 or over 60, you can write a health code.
The health code is based on real data, which is declared by citizens on the Internet. After background review, the personal QR code can be generated. 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.