How did the health card algebra of Healthy Nanjing app come from?

Step 1: Download the "Jiangsu Government Service" APP, then install and log in (as shown in the figure below);

Step 2: Find the "Su Kang code" on the homepage, and new users need to register and log in (as shown in the figure below);

Step 3: Then enter and click "Enter Application" (as shown below);

Step 4: Then enter, improve the health declaration information, confirm that the information is correct, and click "Activate license code" (as shown in the figure below);

Step 5: Then select "Su Kang Code (Nanjing)" to receive the Nanjing health code (as shown in the figure below).