I have signed with the same Google account on my iPhone and iPad. Why are my lists not synchronized?

I have signed with the same Google account on my iPhone and iPad. Why are my lists not synchronized?

Google sign-in sets up your user profile and allows you to get our free “food management at home” course.  To get your products, inventory, and shopping lists synched in real-time on multiple devices and managed between the different user’s profiles, you need to upgrade to CozZo cloud, which is included in our “Household Account” plans.