Originally Posted by
italdesign
You mean the QR code will only appear in Wechat for 24hr, but screenshot will do after that; OR even screenshot will expire after 24hr?
The focus is on the flight that actually brings you into China (e.g. you even need to provide your actual seat number). WeChat is just a distributor channel for the system. The data resides on China government servers.
ETA Completing the form over a stable internet connection and grabbing a screenshot of the qr code is definitely a good idea, but you might be asked to update it upon arrival.