The most likely reason for failing to receive a password reset email is if you are somehow inadvertently trying to use the wrong email account, one that is not registered as a Google Nest account.
If that's not the reason, you could try contacting Support:
1. Go to https://support.google.com/googlenest/gethelp. 2. Select a category/product family, and type in a brief description of the issue, then click "Next". 3. Select your device from the dropdown, click "Other", then click "Next step". 4. Under "Resources", just click "Next step". (Clicking one of the listed links will bring up a Help page.) 5. Under "Contact options", choose to get a phone call or chat with the team, depending on availability in your country.
