Whenever I'm confronted with requests for random health codes, my first response is to say "I don't speak Chinese", and this works 90% of the time.

For the other 10% (e.g. checking in for UA857), somebody will give you a QR code, and tell you exactly what to do.

Screenshots are definitely useful, but if you limit yourself to Wechat and Ali, you can pull up the live versions with ease. Our Shanghai green codes don't have 5 stars at present, and everybody knows this.