Open wechat, my, service, epidemic prevention health code, check health? Click Login, select the communication big data travel card, jump to the applet, and click Query to see the travel code.
Communication Big Data Travel Card is a free inquiry service provided by China ICT Institute, China Telecom, China Mobile and China Unicom for mobile phone users in China. Mobile phone users can query all the city information they have visited in the previous 14 days through this service.