@CKL : is this on a laptop or desktop type device, or a phone or tablet?
On a phone or tablet, the "Camera" app usually scans QR codes and then it will provide an option to open that link, which will go into your default browser.
Or if you mean in Firefox on Android directly, tap in the URL bar, delete any text currently in there, then tap the icon on the right side. Tap "Try it now" if asked about Google Lens. Then on the next screen tap the QR code mode icon at the bottom, then scan your QR code. Then tap "Allow" to let Firefox open that site.
