As of Friday, over 15,000 residents in the Meilisi Daur district of Qiqihar, Heilongjiang province, received the cards printed with their personalized QR codes, with which they can easily finish the nucleic acid testing or enter a public venue without a smart phone.

To solve the problem of scanning codes for residents without smart phones, especially the elderly, the district government has worked with local public security departments to promote the "reverse scanning".

Residents will only need to show the card with a personalized QR code before entering a facility and staff from the facility can scan the code with an application.

"With a green code showed on the staff's phone, visitors can enter the facility and their traces will be also recorded," said Zhuang Tiyong, Party secretary of the district's commission for political and legal affairs, who is in charge of the project. "Inspiration comes from mobile payment, with which we can scan the sellers' payment code or be scanned the payment code in our phones."