Facebook native ad can't click，no reaction

I added facebook native advertising in the iOS app , advertising display, but when I click on the ads is no response, not pop-up advertising content in detail , What's the problem？

FBNativeAd *nativeAd = [[FBNativeAd alloc] initWithPlacementID:fanID];
nativeAd.delegate = self;
[nativeAd loadAd];

- (void)nativeAdDidLoad:(FBNativeAd *)nativeAd{
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), ^{
    NSData *iconImageData = [NSData dataWithContentsOfURL:nativeAd.icon.url];
    NSData *coverImageData = [NSData dataWithContentsOfURL:nativeAd.coverImage.url];
    dispatch_async(dispatch_get_main_queue(), ^{
        int adViewCount = (int32_t)[_nativeAdViewArr count];
        [self genAdScrollView];
        PCNativeAdView *adView = [PCNativeAdView initWithNib];
        CGRect rect = adView.frame;
        rect.origin.x = (rect.size.width + 10)*adViewCount;
        adView.frame = rect;
        [_adScrollView addSubview:adView];
        [_nativeAdViewArr addObject:adView];
        [_adScrollView setContentSize:CGSizeMake((rect.size.width + 10)*(adViewCount + 1), 189)];
        adView.adIconImageView.image = [UIImage imageWithData:iconImageData];
        adView.adCoverImageView.image = [UIImage imageWithData:coverImageData];

        adView.adTitleLabel.text = nativeAd.title;
        adView.adBodyLabel.text = nativeAd.body;
        adView.adSocialContextLabel.text = nativeAd.socialContext;

        NSLog(@"Register UIView for impression and click...");
        [nativeAd registerViewForInteraction:adView
                          withViewController:self];
        if ([_nativeAdViewArr count] == 3)
        {
            [self reloadSubViewRect:-1];
        }
    });
});

}