title: How to add "Touch Id" with "In app Purchase" in Objective c?
body: <p>I have successfully implemented "In App Purchase" in my project and now i am trying to implement a "Touch Id" to buy a product except asking a "Sign in to iTunes" popup. Here in my code it asks "touch id" and "Sign in to iTunes" popup both one after another, why this one wired both things i want only "touch id" to buy product. I have gone for IAP <a href="https://stackoverflow.com/questions/19556336/how-do-you-add-an-in-app-purchase-to-an-ios-application">How do you add an in-app purchase to an iOS application?</a> and for Touch ID <a href="https://stackoverflow.com/questions/37826095/how-do-i-integrate-touch-id-for-my-iap">How do i integrate Touch ID for my IAP?</a> but not getting proper way to implement a touch id for IAP.Here is the code i have added,<a href="https://i.stack.imgur.com/AFPiE.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/AFPiE.jpg" alt="enter image description here"></a></p>
  
  <p>Is this possible through code or it shows apple at the time of buying a product from app store.
  Check above snapshot,</p>
  
  <pre><code>#import &lt;LocalAuthentication/LocalAuthentication.h&gt;
  
  -(void) localAunthentication  
  {
      //LocalAuthentication
      LAContext *authContext = [[LAContext alloc] init];
      NSError *authError = nil;
      NSString *authLocalizedReasonString = @"Please aunthenticate to proceed";
  
      if ([authContext canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&amp;authError])
      {
          [authContext evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics
                      localizedReason:authLocalizedReasonString
                                reply:^(BOOL success, NSError *error)
           {
               if (success)
               {
                   // Allocated here for succinctness.
                   NSOperationQueue *operationQueue = [[NSOperationQueue alloc] init];
  
  
                   [operationQueue addOperationWithBlock: ^
                    {
  
  
                    }];
               }
               else
               {
                   switch (error.code)
                   {
                       case LAErrorAuthenticationFailed:
                           //Authentication Failed
                           break;
  
                       case LAErrorUserCancel:
  
  
  
                           break;
  
                       case LAErrorUserFallback:
  
  
                           break;
  
                       default:
                           //Touch ID is not configured
                           break;
                   }
                   NSLog(@"%@",error.localizedDescription);
  
               }
           }];
      }
      else
      {
      }
  }
  </code></pre>
  
  <p>What should i do to asks only "Touch Id" instead of "Sign in To iTunes" popup. </p>