title: The request was missing an Authentication Key with push notification in firebase
body: <p>I'm trying to send a push notification via REST API Firebase by Postman for specific user I followed below request pattern:</p>
  <p>POST request with below <strong>URL</strong> :</p>
  <p><a href="https://fcm.googleapis.com/fcm/send?key=**my" rel="nofollow noreferrer">https://fcm.googleapis.com/fcm/send?key=**my</a> Web API key**</p>
  <p>and the <strong>Body</strong> is</p>
  <p>{ &quot;data&quot;:
  {
  &quot;title&quot;: &quot;Firebase notification&quot;,
  &quot;detail&quot;: &quot;I am firebase notification. you can customise me. enjoy&quot;
  },
  &quot;to&quot; : &quot;<strong>USER UID</strong>&quot;
  }</p>
  <p>but the problem is it returns  <code>The request was missing an Authentication Key.</code></p>