foregroundNotificationConfig property

If this is set then the services is started as a Foreground service with a persistent notification showing the user that the service will continue running in the background.

Note: Using this foreground notification does not run your service in the background, it just increases the priority of your activity making it less likely for Android to kill the activity when switching between apps. It does not prevent Android from killing the activity. If you want to receive background location updates even if the activity is destroyed you need to use a third party background service package that will start a new Flutter Engine that is not tied to your main activity.