Per the directions:
How to scan a QR code with the Camera app
Open the Camera app from the Home Screen, Control Centre or Lock Screen. Select the rear-facing camera. Hold your device so that the QR code appears in the viewfinder in the Camera app. Your device will recognise the QR code and display a notification. Tap the notification to open the link associated with the QR code.
What's meant by "tap the notification" above? Because this results in a picture of the QR code on my iPhone 8. There's no notification that I see at all.