Go to <a href="https://developers.google.com/maps/documentation/javascript/get-api-key" target="_blank">https://developers.google.com</a> and <a href="https://console.cloud.google.com/google/maps-apis/overview">generate the API key</a> and insert here. This API key needs for show Advanced Google Map widget correctly. API Key also works for Google Review widget so you must enabled Places API too.