I am currently try to use face recognition in flutter, but I want to know is there a way to track user face... I mean I want to ensure that the user who do face recognition is true person according their photo image inside my database
As you must be knowing, Flutter is a mobile app development framework. Something like face recognition is far away from this. You need to keep these separate.
In the Flutter app, you focus on the app design, UI etc. And build a separate face recognition module. There are some face recognition libraries available to use freely. Make use of that. And then integrate the two by means of say REST APIs. One such face recognition library is opencv.