I've learned to write down the Setup Codes and Serial Numbers for our Google Nest cameras and doorbells because of this. The best I can suggest is the following to view the the back of your doorbell to get the Setup Code:
If you have the newer Google Nest Doorbell (Battery), you can insert the release tool (or a small flathead screwdriver) into the slot in the TOP of the doorbell's mounting bracket to remove the doorbell from its mounting bracket, as shown starting at 3:35 in the first video on this Google Nest Help page:
If you have the older Google Nest Hello Doorbell, you can insert the release tool (or a small nail) into the small hole in the BOTTOM of the doorbell's mounting bracket to remove the doorbell from its mounting bracket, as shown starting at 6:25 in the video on this Google Nest Help page:
(I've seen some posts from customers who've had trouble with this, due perhaps to defects in their mounting brackets, so I thought the visuals might help. I'm just another Nest customer, but it's worked for us for our Nest Hello doorbells.)
Appreciate your answer and suggestions, MplsCustomer.
@Ronpierce, I'm dropping by to check if everything is covered here. Feel free to reply back if you still have some questions.