Apple Sign In - "Sign up not completed" Error in Development Build (React Native / Expo)
Problem Summary
I'm implementing Apple Sign In in a React Native app using expo-apple-authentication. The Apple sign-in dialog appears as expected, but after tapping "Continue," it displays the message: "Sign up not completed". No credential is returned, and the promise eventually rejects with ERR_REQUEST_CANCELED.
App Configuration
Platform: React Native (Expo SDK 52)
Library: expo-apple-authentication v7.1.3
Target: iOS development build (not Expo Go)
Bundle ID: com.example.appname.nativetest (new App ID created for testing)
Apple Developer Console Setup (Reviewed Carefully)
App ID
Explicit App ID (not a wildcard)
"Sign In with Apple" capability enabled
No associated Services IDs or Sign In with Apple Keys
Provisioning Profile
Development profile created for the test App ID
Profile includes the test device and development certificate
Installed successfully and used to sign the app
Certificates and Signing
Valid Apple Developer Program membership
Development certificate installed and selected during build
App installs and launches properly on the test device
Implementation Attempts
Attempt 1: Supabase OAuth Method
Initially tried using Supabase’s built-in Apple OAuth provider:
Configured with team ID, key ID, and JWT credentials
Proper redirect URLs and scheme were in place
Resulted in OAuth URL pointing to Supabase instead of Apple, with incomplete client ID
Ultimately moved to native implementation for improved control and reliability
Attempt 2: Native Apple Sign In (Current Approach)
Using expo-apple-authentication with the following code:
const credential = await AppleAuthentication.signInAsync({
requestedScopes: [
AppleAuthentication.AppleAuthenticationScope.FULL_NAME,
AppleAuthentication.AppleAuthenticationScope.EMAIL,
],
});
Relevant app.config.js Section:
ios: {
bundleIdentifier: 'com.example.appname.nativetest',
usesAppleSignIn: true,
infoPlist: {
NSAppTransportSecurity: {
NSAllowsArbitraryLoads: true,
NSAllowsLocalNetworking: true,
},
},
},
plugins: ['expo-apple-authentication']
Observed Behavior
AppleAuthentication.isAvailableAsync() → true
Credential state → NOT_FOUND (expected for new user)
Apple Sign In dialog appears and allows interaction
User taps "Continue" → dialog reports "Sign up not completed"
Eventually returns: [Error: The user canceled the authorization attempt], code ERR_REQUEST_CANCELED
Confirmed Working Aspects
AppleAuthentication API is available and initialized
App is signed correctly and launches on the physical test device
Apple Sign In dialog appears with correct styling and options
Same result observed across both Wi-Fi and cellular networks
Clean Setup and Debugging Performed
Removed all previous build artifacts
Created a new App ID and new provisioning profile
Rebuilt the app using expo run:ios --device
Validated entitlements and provisioning assignments
Removed any Services IDs and Apple Sign In keys used in previous attempts
Verified ATS (App Transport Security) policies allow dev-time communication
Environment Information
Device: iPhone (not simulator)
iOS Version: 18.5
Xcode: Latest version
Apple ID: Developer account with 2FA enabled
Build Method: EAS CLI using expo run:ios --device
Open Questions
Has anyone experienced the "Sign up not completed" issue with a clean native implementation in Expo?
Are there known limitations when testing Apple Sign In in local development builds?
Could prior Apple ID authorization attempts impact sign-in behavior during testing?
Are there any additional configuration steps, Info.plist changes, or entitlements required beyond those listed above?
Thank you in advance for any suggestions or guidance. We’re hoping this is simply a configuration detail that needs to be adjusted.