Lock exposure on the preview of the photo capture in SwiftUII

Good afternoon!

Can you advise, I want to implement photo exposure fixing by clicking on photo preview point, at the moment I use DragGesture to get CGPoint and pass it to capture setup

let device = self.videoDeviceInput.device
        do {
            try device.lockForConfiguration()
            if device.isFocusPointOfInterestSupported {
                device.exposurePointOfInterest = focusPoint
                device.exposureMode = .autoExpose
                device.unlockForConfiguration()
            }
        }

The values are printed to the terminal, but in the preview it feels like one point closer to the bottom edge is being used.

The code for the view is:

.gesture(
DragGesture(minimumDistance: 0)
    .onChanged({ value in
          self.expFactor = value.location
          print(expFactor)
    })
    .onEnded({ value in
          model.exp(with: expFactor)
})

Can you tell me if anyone has already tried to implement the fixing in SwiftUI, I want it roughly like the standard camera.