<service 
    android:name=".java.MyFirebaseMessagingService"
    android:exported="false">
    <intent-filter>
        <action android:name="com.google.firebase.MESSAGING_EVENT" />
    </intent-filter>
</service>

using UnityEngine;
using Singular;
using Firebase.Messaging;
using System.Threading.Tasks;

public class UninstallTrackingManager : MonoBehaviour
{
    async void Start()
    {
        // Initialize Firebase
        await InitializeFirebase();

        // Get FCM token and register it with Singular
        await RegisterFCMToken();

        // Initialize Singular SDK after registering the token
        SingularSDK.InitializeSingularSDK();
    }

    private async Task InitializeFirebase()
    {
        var dependencyStatus = await Firebase.FirebaseApp.CheckAndFixDependenciesAsync();

        if (dependencyStatus == Firebase.DependencyStatus.Available)
        {
            Debug.Log("Firebase is ready");
        }
        else
        {
            Debug.LogError($"Could not resolve Firebase dependencies: {dependencyStatus}");
        }
    }

    private async Task RegisterFCMToken()
    {
        try
        {
            // Get FCM token
            string token = await Firebase.Messaging.FirebaseMessaging.GetTokenAsync();

            if (!string.IsNullOrEmpty(token))
            {
                // Register token with Singular BEFORE SDK initialization
                SingularSDK.RegisterTokenForUninstall(token);
                Debug.Log($"FCM token registered with Singular: {token}");
            }
            else
            {
                Debug.LogWarning("FCM token is empty");
            }
        }
        catch (System.Exception ex)
        {
            Debug.LogError($"Error getting FCM token: {ex.Message}");
        }
    }
}

using UnityEngine;
using Singular;
using Firebase.Messaging;

public class FCMTokenRefreshHandler : MonoBehaviour
{
    void Start()
    {
        // Subscribe to token refresh event
        Firebase.Messaging.FirebaseMessaging.TokenReceived += OnTokenReceived;
    }

    void OnDestroy()
    {
        // Unsubscribe when destroyed
        Firebase.Messaging.FirebaseMessaging.TokenReceived -= OnTokenReceived;
    }

    private void OnTokenReceived(object sender, Firebase.Messaging.TokenReceivedEventArgs e)
    {
        Debug.Log($"New FCM token received: {e.Token}");

        // Update token with Singular
        SingularSDK.RegisterTokenForUninstall(e.Token);

        // Also send token to your server if needed
        SendTokenToServer(e.Token);
    }

    private void SendTokenToServer(string token)
    {
        // Implement your server communication logic here
        Debug.Log($"Sending token to server: {token}");
    }
}

using UnityEngine;
using Singular;

#if UNITY_IOS
using Unity.Notifications.iOS;
#endif

public class iOSUninstallTracking : MonoBehaviour
{
    void Start()
    {
        #if UNITY_IOS
        // Initialize Singular SDK first
        SingularSDK.InitializeSingularSDK();

        // Request notification authorization
        RequestNotificationAuthorization();
        #endif
    }

    #if UNITY_IOS
    private void RequestNotificationAuthorization()
    {
        var authorizationOption = AuthorizationOption.Alert | 
                                  AuthorizationOption.Badge | 
                                  AuthorizationOption.Sound;

        using (var req = new AuthorizationRequest(authorizationOption, true))
        {
            while (!req.IsFinished)
            {
                // Wait for authorization
            }

            string deviceToken = req.DeviceToken;

            if (!string.IsNullOrEmpty(deviceToken))
            {
                // Convert device token to hex string and register with Singular
                SingularSDK.RegisterTokenForUninstall(deviceToken);
                Debug.Log($"APNS token registered: {deviceToken}");
            }
            else
            {
                Debug.LogWarning("Failed to get APNS device token");
            }
        }
    }
    #endif
}