Why is the nucleic acid code in the health cloud no longer used?

Why can't the nucleic acid code be used suddenly? What happened? Because the current flow of nucleic acid cryptography system is limited, resulting in access congestion, you can try again later. In addition, on-site sampling registration also supports physical identity documents, so everyone can also use identity documents as nucleic acids. In addition, in order to use the nucleic acid code more conveniently, you can apply for the nucleic acid code and save it by screen capture or print it out for use, because the nucleic acid code can be reused within 30 days after application, which is very convenient.