title: Firebase Notifications - How to Send Notifications only to Specific Users?
body: <p>I'm building an app using Firebase Notifications where a user can enter their zip code and then receive notifications for specific events happening in their locality.</p>
  
  <p>How do I only send notifications to a specific user? I've tried including Zip Code in the <em>Advanced Options</em> sections of Firebase Notifications, but it still sends the notification to all users.</p>