Here's a quick guide how to get your QR code (二维码 èrwéimǎ ) for a Nuclead Acid Test (新冠病毒核酸检测 xīn guàn bìng dú hé suān jiǎn cè) in Shanghai.
1) Download the Health Cloud App. Search for 健康云 on the Apple App store or Google Play Store and install the app
2) Click the Icon that says 核酸检测服务
3) If you've previously used the app, and you want to get the QR code for yourself, click the icon that looks like a QR code and says 我的登记码. Each code is valid for the same day only. If you haven't created a code today, a message will pop up informing you that you have no valid code. Click the blue 是 button to create a new code. You'll be shown the registration form once more, just click confirm.
4) If you previously haven't used the app, click the big orange button to register yourself or someone else for the app
5) Fill out the form