QR code and Setup Key rubbed off back of Doorbell

[Jollywood]

We some adhesive product to help secure doorbell when mounting. When I took it down, all info has worn off the back - QR code, setup key, serial number - all disappeared. 
I changed network, and need to reset doorbell to re-add it to Home. How can I do this without the above for mentioned info. 
thanks for the help!!! 

[MplsCustomer]

@Jollywood 

Unfortunately, you cannot install or re-install a Google Nest camera without either the QR code or the Setup Code. The new 2nd gen battery cameras come with the QR code printed on a sticker affixed to the front of the camera, and the install instructions suggest saving that sticker in the camera's Quick Start Guide.

Because of this issue, we have for years written down the 6-character alphanumeric Setup Code for each of our cameras and doorbells.