More than 38 users adopted TA's answer.
this is because
First, the network signal is poor, resulting in the health code can not be displayed normally;
2. My personal information is incorrect and needs to be re-filled;
Third, because you are not logged into the health system, you cannot view the health code. First of all, because the health code needs network support when updating, if we are in a place with poor network, we may not be able to display the health code normally. We can go to a place with a slightly better network or ask the staff for help.