What does it mean to apply for a health code in advance?

Fill in the health code information 3 days in advance.

Health regulations in some areas need to be applied three to five days in advance. The application of health code covers the use scenarios such as community management, resumption of business, transportation, school opening, drug purchase registration, and supermarkets.

Health Code is a tracking and judging system of personal health information and activity information used for epidemic prevention and control in COVID-19. Individuals declare online by themselves, and generate personal two-dimensional code after background audit, which can be used as an electronic certificate for individuals to enter and leave a certain area, realizing one-time declaration and local use.