When did the bar on the local code become an arrow?

After scanning the code. Because when you enter a public place and scan the "place code", you can enter the place when a green arrow appears, so when you scan the code, the column will become an arrow. The "place code" is a special two-dimensional code given by a specific place. On the basis of automatically verifying the "health code" information, the information of people entering the place is automatically registered.