How can I start a ViewController from within a Method?

I want to use the TGCameraViewController from within a iOS Cordova Plugin method.

Here is the implementation of the method:

#import "BCamera.h"
#import "TGCameraViewController.h"

@implementation BCamera

// Cordova command method
-(void) openCamera:(CDVInvokedUrlCommand *)command {

// take a photo

}

From the documentation of the TGCameraViewController I have to use the following to take a photo:

#import "TGCameraViewController.h"

@interface TGViewController : UIViewController <TGCameraDelegate>

@property (strong, nonatomic) IBOutlet UIImageView *photoView;

- (IBAction)takePhotoTapped;

@end



@implementation TGViewController

- (IBAction)takePhotoTapped
{
    TGCameraNavigationController *navigationController =
    [TGCameraNavigationController newWithCameraDelegate:self];

    [self presentViewController:navigationController animated:YES completion:nil];
}

#pragma mark - TGCameraDelegate optional

- (void)cameraWillTakePhoto
{
    NSLog(@"%s", __PRETTY_FUNCTION__);
}

- (void)cameraDidSavePhotoAtPath:(NSURL *)assetURL
{
    // When this method is implemented, an image will be saved on the user's device
    NSLog(@"%s album path: %@", __PRETTY_FUNCTION__, assetURL);
}

- (void)cameraDidSavePhotoWithError:(NSError *)error
{
    NSLog(@"%s error: %@", __PRETTY_FUNCTION__, error);
}

#pragma mark - TGCameraDelegate required

- (void)cameraDidTakePhoto:(UIImage *)image
{
    _photoView.image = image;
    [self dismissViewControllerAnimated:YES completion:nil];
}

- (void)cameraDidCancel
{
    [self dismissViewControllerAnimated:YES completion:nil];
}

@end

How do I use this example to open the camera view from within my openCamera method?