Enable Voice Match on your Google Nest device

Unlike Alexa devices, Google Nest has a feature called “Voice Match,” which learns your voice over time. Once your device knows your voice, no one will be able to use your Google Home except for you, which will prevent third parties from accessing the device for your stored information. To set up Voice Match:

• Select and verify your account in the Google Home app.
• Select Assistant Settings > Voice Match > Add Devices.
• Agree and follow the in-app steps.