title: Disable Legacy Server Key
body: <p>I found that Firebase Cloud Messaging has two ways to send Push Notifications.</p>
  
  <p>I am aware of how the two ways are working and I have already implemented and tested my app and server using both ways.</p>
  
  <p>However, I am required to disable the "Legacy server key" way of sending messages.</p>
  
  <p>I cannot find how to disable this using Firebase Console.</p>
  
  <p>Is it possible to disable the Legacy way of sending Push Notifications? How?</p>