Trying to share application on social median, and email, and message.
Since Email and message is working fine for me. 
But Facebook,and twitter is not all showing to `UIActivityViewController`

Below is code which i try.

```
NSArray *excludeActivities = @[UIActivityTypeAirDrop,
                               UIActivityTypePostToFacebook,
                               UIActivityTypePostToTwitter];
UIActivityViewController *activityViewController =
[[UIActivityViewController alloc] initWithActivityItems:@[string, URL]
                                  applicationActivities:nil];
activityViewController.excludedActivityTypes = excludeActivities;
[self presentViewController:activityViewController
                                   animated:YES
                                 completion:^{
                                 }];

- (id)activityViewController:(UIActivityViewController *)activityViewController
         itemForActivityType:(NSString *)activityType
{
    if ([activityType isEqualToString:UIActivityTypePostToFacebook]) {
        return NSLocalizedString(@"calling facebook", );
    } else if ([activityType isEqualToString:UIActivityTypePostToTwitter]) {
        return NSLocalizedString(@"calling twitter", );
    } else {
        return nil;
    }
}

```

@All
Please let me know what i need to do.