@MplsCustomer, your assistance here is greatly appreciated.
Thanks for posting, @Sd7. Ensure that you're using a personal Google Account to set up your Google Nest Mini since this issue usually shows up when you're using a Google Workspace Account or other email accounts with strong security and privacy configuration.
If you're using a personal email, exit the setup screen and enable voice match in the Google Home app. Here's how: open the Google Home app > Tap the Account icon at the top right > Choose Assistant Settings > Hey Google & Voice Match > Other devices > Tap on the device name that you're currently setting up > If it asks you to turn on voice match, follow the on-screen prompts.
Let me know how it goes.