Hi espumita62,
Thanks for posting in the Google Nest Community forum. I'm sorry for the delay. A few questions: what type of Nest Thermostat do you have? Also, in what country are you located?
If you have the Nest Thermostat 2020, you can scan the QR code on the back of your thermostat display.
Tip: If the scan is unsuccessful, you can tap Continue without scanning. Select the thermostat you are setting up and enter the code on the back of the thermostat display.
If you have the Nest Learning Thermostat or Nest Thermostat E, you can go to your thermostat's Quick View menu > Settings > Nest app > Entry Key.
Let me know how it goes.
Best,
Jenelyn
