How do I upload a file to my dropbox apps folder in dropbox in objective c?

In my app delegate method I checked to see if the session was linked and from my test the logs states that my session is linked.

if ([[DBSession sharedSession] isLinked]) {

    NSLog(@"The session IS linked");

  } else {

    NSLog(@"The session is not linked");

  }

I have checked my app console and is says that one users is connected to the app and it also says that I made one API call yesterday. However I don't see the test  image that I wast trying to upload to dropbox. I am wondering if  I am uploading the file incorrectly. This is my upload method

• (void)uploadToDropBox:(UIImage *)img

{

  UIImage *testPic = [UIImage imageNamed:@"IMG_0005.jpg"];

  NSArray *directories = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,

                                                             NSUserDomainMask,

                                                             YES);

  NSString *documentDirectory = [directories firstObject];

  NSString *imagePath = [documentDirectory stringByAppendingPathComponent:@"cardImage"];

  NSString *destDir = @"/";

  NSData *imageData = UIImagePNGRepresentation(testPic);

  [imageData writeToFile:imagePath atomically: YES];

  [self.restClient uploadFile:@"cardImage" toPath:destDir withParentRev:nil fromPath:imagePath];

  [self sendBDayCard];

}