add $notificationId to every broadcast notification

app/Events/UserCreated.php

@@ -15,13 +15,15 @@ class UserCreated implements ShouldBroadcastNow
 
 
     public $user;
+    public $notificationId;
 
     /**
      * Create a new event instance.
      */
-    public function __construct(User $user)
+    public function __construct(User $user, $notificationId)
     {
         $this->user = $user;
+        $this->notificationId = $notificationId;
     }
 
     /**