Retweet using STTwitter API

Question

I have tried to add the retweet concept in my application using STTwitter API with following method after user authentication:

[twitter postStatusRetweetWithID:[NSString stringWithFormat:@"691544087921606656"] successBlock:^(NSDictionary *status) {
       NSLog(@"status..%@",status);
   } errorBlock:^(NSError *error) {
       NSLog(@"error..%@",error);
   }];

But it is showing following error:

Error Domain=STTwitterTwitterErrorDomain Code=220 "Your credentials do not allow access to this resource." UserInfo={NSUnderlyingError=0x7b170ca0 {Error Domain=STHTTPRequest Code=403 "HTTP Status 403: Forbidden" UserInfo={NSLocalizedDescription=HTTP Status 403: Forbidden}}, NSLocalizedDescription=Your credentials do not allow access to this resource.}

If anyone has experienced with the STTwitter API. Suggest me some idea to get rid from this error.

Thanks in advance.