Getting an error: 'UIAlertView' is deprecated: first deprecated in iOS 9.0 - UIAlertView is deprecated

Question

I'm developing a mobile app with Flutter. I realized the app in Android but I'm stuck with iOS. I have this error message that I don't know how to fix.

This error appears with the plugin Geolocator.

- (void)showCamera {
  @synchronized(self) {
    if (_imagePickerController.beingPresented) {
      return;
    }
  }
  // Camera is not available on simulators
  if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera] &&
      [UIImagePickerController isCameraDeviceAvailable:_device]) {
    _imagePickerController.sourceType = UIImagePickerControllerSourceTypeCamera;
    _imagePickerController.cameraDevice = _device;
    [[self viewControllerWithWindow:nil] presentViewController:_imagePickerController
                                                      animated:YES
                                                    completion:nil];
  } else {
    [[[UIAlertView alloc] initWithTitle:NSLocalizedString(@"Error", nil)
                                message:NSLocalizedString(@"Camera not available.", nil)
                               delegate:nil
                      cancelButtonTitle:NSLocalizedString(@"OK", nil)
                      otherButtonTitles:nil] show];
      
    self.result(nil);
    self.result = nil;
    _arguments = nil;
  }
}

So the error is:

'UIAlertView' is deprecated: first deprecated in iOS 9.0 - UIAlertView is deprecated. Use UIAlertController with a preferredStyle of UIAlertControllerStyleAlert instead'