Where did the nucleic acid paste first appear?

The nucleic acid paste first appeared in Xi 'an. Since March, the epidemic has blossomed in many places, and sporadic outbreaks and local large-scale epidemics have occurred in major cities across the country. In order to cope with the epidemic situation, prevent and control it accurately, and avoid the influence of network problems on nucleic acid collection, personalized stickers have been launched all over the country. On April 15, a new round of nucleic acid screening was carried out in Xi City, Shaanxi Province. After the nucleic acid test is completed, citizens will receive the "Huo Qubing" sticker as valid proof before the test results come out. Since March 12 this year, Xi has launched the first sticker for nucleic acid detection coupons, from "Qing Si Bao" to "Shoutian Tuan in the Prosperous Tang Dynasty" and then to the famous Huo Qubing. So far, nine cartoon characters have been released.