Look on the electronic application website to see if there is a 002 certificate. Certificates have a validity period. Select the corresponding certificate in the upper right corner of the browser - Tools - Internet Options - Content - Certificate, and double-click to view the certificate. If the number of years has exceeded, you can mail a paper certificate to the State Intellectual Property Office to apply for re-downloading. The process will take about 15 days, and the certificate number will become 002