You can try going into settings -> screen time -> Content and Privacy Restrictions

Make sure there aren't any website restrictions turned on.

Hi ssdct,

It seems you're having trouble scanning a QR code and we can help.

Try taking the steps for when your camera is not working as expected:

If the camera or flash on your iPhone, iPad, or iPod touch isn't working

Inspect the lens for your iPhone and take some pictures in a bright area and inspect them carefully, it's possible your iPhone has an issue with debris or an anomaly on the lens that's interfering with reading the QR code correctly.

Let us know if that helps.

Thanks for using the Apple Support Communities.