How to open camera to scan QR code into Google Form field?

Question

We use Google Forms to track entry into certain events. Staff and attendees enter their ID number which is handed out with a QR code.

I have been tasked with trying to figure out how we can access the iPads cameras (we use iPads for the forms) to scan attendees' QR codes and have their ID number from the code entered into the correct field in the form.

I believe we can use Google Apps Script somehow, but I am unsure.