title: Request is missing required authentication credential
body: <p>I am trying to send FCM message through POSTMAN. I have added the server key, the one from cloud messaging in settings of firebase console.</p>
  
  <p><a href="https://i.stack.imgur.com/4CLDe.png" rel="noreferrer"><img src="https://i.stack.imgur.com/4CLDe.png" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/hJzJ7.png" rel="noreferrer"><img src="https://i.stack.imgur.com/hJzJ7.png" alt="error"></a></p>
  
  <p>What is missing here?</p>