Sign in with Apple uses correct button styling if social login exists

Apple Guideline 4.8 requires that Sign in with Apple be offered whenever any other social login (Google, Facebook, Twitter) is available in an iOS app. Violation causes rejection. Beyond the guideline, Apple mandates use of its official button component (AppleAuthenticationButton) with approved styles — a custom-colored button that calls the Apple auth API but renders as a blue pill violates the Human Interface Guidelines and triggers rejection during review. CWE-284 (Improper Access Control) applies when the requirement is absent entirely: users who want Apple's privacy-preserving login (hide-my-email) are denied that option, pushing them toward more data-exposing alternatives.

Replace any custom sign-in button with the official Expo component:

import * as AppleAuthentication from 'expo-apple-authentication';

<AppleAuthentication.AppleAuthenticationButton
  buttonType={AppleAuthentication.AppleAuthenticationButtonType.SIGN_IN}
  buttonStyle={AppleAuthentication.AppleAuthenticationButtonStyle.BLACK}
  cornerRadius={5}
  style={{ width: '100%', height: 44 }}
  onPress={handleAppleSignIn}
/>

Do not wrap this in a custom TouchableOpacity or restyle it — Apple validates button authenticity during review. Ensure the Sign in with Apple button is the same height and visual weight as any Google or Facebook login button on the same screen. Enable the Sign in with Apple capability in ios/[AppName].entitlements and in App Store Connect under the app's capabilities before submission.