diff --git a/messaging/app/build.gradle b/messaging/app/build.gradle
index 02fc3ef37..806380e48 100644
--- a/messaging/app/build.gradle
+++ b/messaging/app/build.gradle
@@ -58,6 +58,12 @@ dependencies {
     // Firebase Cloud Messaging (Kotlin)
     implementation 'com.google.firebase:firebase-messaging-ktx'
 
+    // Cloud Functions for Firebase (Java)
+    implementation 'com.google.firebase:firebase-functions'
+
+    // Cloud Functions for Firebase (Kotlin)
+    implementation 'com.google.firebase:firebase-functions-ktx'
+
     // For an optimal experience using FCM, add the Firebase SDK
     // for Google Analytics. This is recommended, but not required.
     implementation 'com.google.firebase:firebase-analytics'
diff --git a/messaging/app/src/main/java/com/google/firebase/quickstart/fcm/java/MainActivity.java b/messaging/app/src/main/java/com/google/firebase/quickstart/fcm/java/MainActivity.java
index 3194e8f36..5750b59cd 100644
--- a/messaging/app/src/main/java/com/google/firebase/quickstart/fcm/java/MainActivity.java
+++ b/messaging/app/src/main/java/com/google/firebase/quickstart/fcm/java/MainActivity.java
@@ -29,10 +29,15 @@
 
 import com.google.android.gms.tasks.OnCompleteListener;
 import com.google.android.gms.tasks.Task;
+import com.google.firebase.functions.FirebaseFunctions;
+import com.google.firebase.functions.HttpsCallableReference;
 import com.google.firebase.messaging.FirebaseMessaging;
 import com.google.firebase.quickstart.fcm.R;
 import com.google.firebase.quickstart.fcm.databinding.ActivityMainBinding;
 
+import java.util.HashMap;
+import java.util.Map;
+
 public class MainActivity extends AppCompatActivity {
 
     private static final String TAG = "MainActivity";
@@ -97,26 +102,46 @@ public void onClick(View v) {
                 // Get token
                 // [START log_reg_token]
                 FirebaseMessaging.getInstance().getToken()
-                    .addOnCompleteListener(new OnCompleteListener<String>() {
-                        @Override
-                        public void onComplete(@NonNull Task<String> task) {
-                          if (!task.isSuccessful()) {
-                            Log.w(TAG, "Fetching FCM registration token failed", task.getException());
-                            return;
-                          }
-
-                          // Get new FCM registration token
-                          String token = task.getResult();
-
-                          // Log and toast
-                          String msg = getString(R.string.msg_token_fmt, token);
-                          Log.d(TAG, msg);
-                          Toast.makeText(MainActivity.this, msg, Toast.LENGTH_SHORT).show();
-                        }
+                    .addOnCompleteListener(task -> {
+                      if (!task.isSuccessful()) {
+                        Log.w(TAG, "Fetching FCM registration token failed", task.getException());
+                        return;
+                      }
+
+                      // Get new FCM registration token
+                      String token = task.getResult();
+
+                      // Log and toast
+                      String msg = getString(R.string.msg_token_fmt, token);
+                      Log.d(TAG, msg);
+                      Toast.makeText(MainActivity.this, msg, Toast.LENGTH_SHORT).show();
                     });
                 // [END log_reg_token]
             }
         });
     }
 
+    @Override
+    protected void onResume() {
+        super.onResume();
+
+        // [START send_reg_token]
+        FirebaseMessaging.getInstance().getToken()
+                .addOnCompleteListener(task -> {
+                    if (!task.isSuccessful()) {
+                        Log.w(TAG, "Fetching FCM registration token failed", task.getException());
+                        return;
+                    }
+
+                    String token = task.getResult();
+                    Map<String, String> tokenMap = new HashMap<>();
+                    tokenMap.put("fcm_token", token);
+
+                    // Send token to backend server
+                    HttpsCallableReference callable =
+                            FirebaseFunctions.getInstance().getHttpsCallable("updateToken");
+                    callable.call(tokenMap).getResult();
+                });
+        // [END send_reg_token]
+    }
 }
diff --git a/messaging/app/src/main/java/com/google/firebase/quickstart/fcm/kotlin/MainActivity.kt b/messaging/app/src/main/java/com/google/firebase/quickstart/fcm/kotlin/MainActivity.kt
index 7c4ef05a5..d5769bdd8 100644
--- a/messaging/app/src/main/java/com/google/firebase/quickstart/fcm/kotlin/MainActivity.kt
+++ b/messaging/app/src/main/java/com/google/firebase/quickstart/fcm/kotlin/MainActivity.kt
@@ -8,10 +8,14 @@ import android.util.Log
 import android.widget.Toast
 import androidx.appcompat.app.AppCompatActivity
 import com.google.android.gms.tasks.OnCompleteListener
+import com.google.android.gms.tasks.Task
+import com.google.firebase.functions.FirebaseFunctions
 import com.google.firebase.ktx.Firebase
+import com.google.firebase.messaging.FirebaseMessaging
 import com.google.firebase.messaging.ktx.messaging
 import com.google.firebase.quickstart.fcm.R
 import com.google.firebase.quickstart.fcm.databinding.ActivityMainBinding
+import com.google.firebase.quickstart.fcm.java.MainActivity
 
 class MainActivity : AppCompatActivity() {
 
@@ -84,6 +88,32 @@ class MainActivity : AppCompatActivity() {
         Toast.makeText(this, "See README for setup instructions", Toast.LENGTH_SHORT).show()
     }
 
+    override fun onResume() {
+        super.onResume()
+
+        // [START send_reg_token]
+        FirebaseMessaging.getInstance().token
+            .addOnCompleteListener { task: Task<String> ->
+                if (!task.isSuccessful) {
+                    Log.w(
+                        TAG,
+                        "Fetching FCM registration token failed",
+                        task.exception
+                    )
+                    return@addOnCompleteListener
+                }
+                val token = task.result
+                val tokenMap: MutableMap<String, String?> =
+                    HashMap()
+                tokenMap["fcm_token"] = token
+
+                // Send token to backend server
+                val callable = FirebaseFunctions.getInstance().getHttpsCallable("updateToken")
+                callable.call(tokenMap).getResult()
+            }
+        // [END send_reg_token]
+    }
+
     companion object {
 
         private const val TAG = "MainActivity"