I need help with iAds trying to implement iAds in my sprite kit game i read through the apple docs still not working

// GameViewController.m

import "GameViewController.h"

import "TitleScene.h"

import "iAd/iAd.h"

@implementation GameViewController

(void)viewDidLayoutSubviews { ADBannerView *adView = [[ADBannerView alloc] initWithFrame:CGRectZero];

adView.currentContentSizeIdentifier = ADBannerContentSizeIdentifierPortrait;

[self.view addSubview:adView];
// GameViewController.h // Space Cat //

// Copyright (c) 2016 George Gutieres. All rights reserved. //

import <UIKit/UIKit.h>

import <SpriteKit/SpriteKit.h>

import <iAd/iAd.h>

@interface GameViewController : UIViewController <ADBannerViewDelegate>

@end