title: What Bearer token should I be using for Firebase Cloud Messaging testing?
body: <p>I am trying to send a test notification using Firebase Cloud Messaging via Postman.  I'm doing a POST to this url</p>
  
  <pre><code>https://fcm.googleapis.com/v1/projects/[my project name]/messages:send
  </code></pre>
  
  <p>The Authorization tab in Postman is set to No Auth and my Headers tab looks like this</p>
  
  <pre><code>Content-Type: application/json
  Authorization: Bearer [server key]
  </code></pre>
  
  <p>[server key] is a newly generated server key in the 'Cloud Messaging' tab of my Firebase project's 'Settings' area. I keep getting this error in response.</p>
  
  <pre><code>"error": {
      "code": 401,
      "message": "Request had invalid authentication credentials. Expected OAuth 2 access token, login cookie or other valid authentication credential. See https://developers.google.com/identity/sign-in/web/devconsole-project.",
      "status": "UNAUTHENTICATED"
  }
  </code></pre>
  
  <p>Based on everything I can find, I'm using the right token, but it seems Google disagrees.  What should I be sending as the Authorization header to get past this error?</p>