This below copied from another post just does not work and I am unable to share control of the Nest products with my spouse. Do they need a Google account prior to sending them the email?
Plaese advise.
Here are the steps to add someone:
Open the Google Home app.
Switch to the home you want to share.
At the top, tap Add Invite home member Invite person.
If you don't find "Invite home member," tap Add person to home.
Enter the name or email address of the person you want to invite to your home tap Next.
Review what’s shared when you add someone to your home tap Next.
Review the person’s access to your home tap Send.
If your Google Family Group isn’t full and the person you’re inviting isn’t already in one, you’ll get the option to invite them to your Google Family Group.
To invite them, tap Add to Family.
To skip this step, tap No Thanks.
Note: You can have up to 6 members in a Google Family Group.
The person you invite will receive an email with instructions.
