Google pay scanning credit card without camera permission

I have [Google Pay](https://play.google.com/store/apps/details?id=com.google.android.apps.walletnfcrel) installed on my phone. I have denied camera permission for every single app (except for "Settings" app which I am unable to deny Camera permission) on my phone. When I try to add payment method on Google Pay app, Google Pay app is able to use my phone camera to scan credit card without camera permission. How is this possible?