The script has an unsupported MIME type ('text/html'). Unable to resolve using firebase-messaging-sw.js

I am getting this error, The script has an unsupported MIME type ('text/html'). Unable to resolve using firebase-messaging-sw.js.

  const messaging = firebase.messaging();
  messaging.requestPermission().then(function(){  console.log("have permission");
  return messaging.getToken(); }).then(function(token){
  console.log(token)
  }).catch(function(err){
  console.log("Error");
  })