How to send notification to specific users with FCM?
<p>I prepared the receiver for FCM and can send a notification to all devices. </p>

<p><strong>gcm-http.googleapis.com/gcm/send</strong> with this link can send to target users who is registered and post to the target devices like below json : </p>

<pre><code> {
     "notification": {
                "title": "sample Title",
                "text": "sample text"   },   
        "to" : "[registration id]"
         }
</code></pre>

<p>However, I need to send notifications to target users which I choose,
via email or name...etc .
For example: </p>

<pre><code>{
     "notification": {
                "title": "sample Title",
                "text": "sample text"   },   
        "to" : "[email or name or sex ...]"
         }
</code></pre>

<p>How can I do that? 
Do I need to create a web server or something else?</p>