Moved into house with existing ring doorbell - can't work out how to set it up

I've followed the instructions here https://ring.com/support/articles/k8jn9/transfer-device-ownership, however there is no visible QR code on the ring doorbell attached to the door. Do I need to remove it - i.e. would QR code be on the back? If so - how do I go about doing that? Not sure what model it is (have done quite a bit of searching but haven't found a helpful guide anywhere). If anyone has useful advice, that would be much appreciated