Aren't you supposed to add a receiver for a notification? Update your Android Manifest.

// Source - https://stackoverflow.com/a/79829404
// Posted by Bhavin Parghi
// Retrieved 2025-11-25, License - CC BY-SA 4.0

<receiver
    android:name="com.dexterous.flutterlocalnotifications.ScheduledNotificationReceiver"
    android:exported="false" />

<receiver
    android:name="com.dexterous.flutterlocalnotifications.ScheduledNotificationBootReceiver"
    android:exported="false">
    <intent-filter>
        <action android:name="android.intent.action.BOOT_COMPLETED" />
        <action android:name="android.intent.action.MY_PACKAGE_REPLACED" />
    </intent-filter>
</receiver>