As soon as Google my business Review Link is SetUp, start Google my business page (Google Maps Account) Integration.
Setup Social Accounts > Google > Login with Google
(for selected location at right handside)
Sign in and Enter your login credentials of Google My Business (GMB) Account
Choose your correct business location page
And its Done!
Your Google My Business is integration with the Selected Location. You can now Go to the Reviews section in the left navigation bar and start managing it.