Google Maps Integration on Flutter App

We are developing a mobile app on Flutter which will connect to the Blue Collar workers to Employers. Visit www.bluehelmet.in for more information. The front end for the app is complete the freelancer need to integrate with the mobile app & google maps. The account is already created on the Google Cloud. Following are the scope of work :

1. Consent of the location from the user.
2. Placement of Markers on Google Maps as per Lat-Long from the Database.
3. Geo Fencing of the markers on the Google Maps