There are so many third-party apps to scan QR codes on your iPhone. If you want to Scan QR codes from your iPhone then follow the below-given steps:-
Firstly, Download the QR scanner Apps with the help of third-party tools.
Then, Open this app on your iPhone and try to point your camera lens in front of the QR code that you want to scan.
To identify your QR code wait for sometimes and your code will display it.
If you want to open scan QR code contents in other websites or Apps, then Tap on the QR code.
Source:- https://ityug247.com/how-to-scan-qr-code-on-iphone/