Do we have data about how elders use QR codes?

I'm designing an app, and someone has defined that they want the user to login using a QR code in their mobiles and show them in a camera, that will recognise them and allow them to access.

Our persona is an elder woman, from 60 to 80, not very comfortable with technology. And I'm pretty scared that users will drop if they don't understand the flow:

1.Open the app 2.Locate the QR 3.Show it to the camera.

So, do we have data about how elder users use QR's? (In my company user testing it's not well recieved, so unfortunately we can't make test)

Thanks!