OAuth2 to Authenticate Trakt API - Cannot Redirect Back to my App

I'm trying to use the Trakt API to get a list of TV shows and other data. However, I'm stuck on authenticating my app with Trakt. I have my API key, secret, and redirect URI, but am struggling on how to authorise my app. I've tried the following:

Method 1, using the sample code from Trakt:

-(void)authorisation{

    NSString *redirectURI = @"http://myappredirect://";
    NSString *clientID = @"MY_CLIENT_ID";
    NSString *clientSecret = @"MY_CLIENT_SECRET";
    NSString *username = @"USERNAME";
    NSString *authURL = [NSString stringWithFormat:@"http://ift.tt/1Dq7nkU", clientID, redirectURI, username];

    NSURL *URL = [NSURL URLWithString:authURL];

    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:URL];
    [request setHTTPMethod:@"GET"];

    [request setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];

    [[UIApplication sharedApplication] openURL:URL];

    NSURLSession *session = [NSURLSession sharedSession];
    NSURLSessionDataTask *task = [session dataTaskWithRequest:request
                                            completionHandler:
                                  ^(NSData *data, NSURLResponse *response, NSError *error) {

                                      if (error) {
                                          // Handle error...
                                          return;
                                      }

                                      if ([response isKindOfClass:[NSHTTPURLResponse class]]) {
                                          NSLog(@"Response HTTP Status code: %ld\n", (long)[(NSHTTPURLResponse *)response statusCode]);
                                          NSLog(@"Response HTTP Headers:\n%@\n", [(NSHTTPURLResponse *)response allHeaderFields]);
                                      }

                                      NSString* body = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
                                      NSLog(@"Response Body:\n%@\n", body);
                                  }];
    [task resume];
}

This opens Safari on my iPhone, loads the web page successfully with Trakt asking to authorise my account for my app. I tap 'Authorize' and then Safari loads a URL 'myappredirect//?code=a_really_long_string_of_characters", but with an error

Safari cannot open the page because the server cannot be found.

When I enter myappredirect:// in Safari, my app opens, so I'm wondering if the URL that Safari loads is incorrect as it's missing a semi-colon before the double //?

So I tried adding a UIWebView to my app and load the URL in there. It loads the URL but this time after I tap 'Authorize', it doesn't change the webpage. The UIWebView delegate webViewDidStartLoad does tell me that it loads a page after I tap 'Authorize', but nothing changes on-screen.

Method 2, using OAuth2Client:

-(void)setupWebview{

    webView = [[UIWebView alloc] initWithFrame:CGRectMake(0, 0, 300, 300)];
    webView.backgroundColor = [UIColor greenColor];
    webView.delegate = self;
    [self.view addSubview:webView];

}

-(void)webViewDidStartLoad:(UIWebView *)webView{
    NSLog(@"webViewDidStartLoad");
}

-(void)secondMethod{
    NSString *redirectURI = @"http://myappredirect://";
    NSString *clientID = @"MY_CLIENT_ID";
    NSString *clientSecret = @"MY_CLIENT_SECRET";
    NSString *username = @"USERNAME";
    NSString *authURL = [NSString stringWithFormat:@"http://ift.tt/1Dq7kph", clientID, redirectURI, username];
    NSString *tokenURL = @"http://ift.tt/1vObedT";

    [[NXOAuth2AccountStore sharedStore] setClientID:clientID
                                             secret:clientSecret
                                   authorizationURL:[NSURL URLWithString:authURL]
                                           tokenURL:[NSURL URLWithString:tokenURL]
                                        redirectURL:[NSURL URLWithString:redirectURI]
                                     forAccountType:@"Trakt"];

    [[NXOAuth2AccountStore sharedStore] requestAccessToAccountWithType:@"Trakt"
                                   withPreparedAuthorizationURLHandler:^(NSURL *preparedURL){
                                       // Open a web view or similar
                                       [webView loadRequest:[NSURLRequest requestWithURL:preparedURL]];
                                   }];
}

-(void)viewWillAppear:(BOOL)animated{
    [super viewWillAppear:YES];

    [[NSNotificationCenter defaultCenter] addObserverForName:NXOAuth2AccountStoreAccountsDidChangeNotification
                                                      object:[NXOAuth2AccountStore sharedStore]
                                                       queue:nil
                                                  usingBlock:^(NSNotification *aNotification){
                                                      // Update your UI
                                                      NSLog(@"Success");
                                                  }];

    [[NSNotificationCenter defaultCenter] addObserverForName:NXOAuth2AccountStoreDidFailToRequestAccessNotification
                                                      object:[NXOAuth2AccountStore sharedStore]
                                                       queue:nil
                                                  usingBlock:^(NSNotification *aNotification){
                                                      NSError *error = [aNotification.userInfo objectForKey:NXOAuth2AccountStoreErrorKey];
                                                      // Do something with the error
                                                      NSLog(@"Error");
                                                  }];
}

Here, I'm not sure what the token URL is. Again, my UIWebView loads the URL perfectly but after I press 'Authorize', it doesn't change its webpage. The delegate method webViewDidStartLoad does tell me that it loads another page, but nothing changes on-screen. Also, neither of the NXOAuth2 notifications are sent.

I'm new to OAuth2 and would really appreciate any help anybody may have to offer. I apologise if this is a silly question, I'm really struggling on what to do, and confused as to why Safari won't open my app after I've authorised Trakt.

Thanks.