Facebook Login

Create Facebook app

1. Create an app on Meta for Developers.

2. Note your Facebook App ID and Client Token.

Android

Add to android/app/src/main/res/values/strings.xml:

<resources>
    <string name="facebook_app_id">YOUR_FB_APP_ID</string>
    <string name="fb_login_protocol_scheme">fbYOUR_FB_APP_ID</string>
    <string name="facebook_client_token">YOUR_CLIENT_TOKEN</string>
</resources>

Replace YOUR_FB_APP_ID with the numeric App ID (the protocol scheme must be fb + ID, no spaces).

iOS

Add to ios/Runner/Info.plist:

<key>FacebookAppID</key>
<string>YOUR_FB_APP_ID</string>
<key>FacebookClientToken</key>
<string>YOUR_CLIENT_TOKEN</string>
<key>FacebookDisplayName</key>
<string>Your App Name</string>

Ensure CFBundleURLTypes also includes the Facebook scheme entry if required by your Facebook SDK version (usually fbYOUR_FB_APP_ID).

Verify

Test login on both platforms; check Meta dashboard for logged events. Invalid token errors usually mean App ID / Client Token mismatch or missing platform configuration in Meta.