Does Amplify AWS does not generate device token on V6 for Push Notification?

According to the latest documentation of Aws Amplify V6 ,to generate token we have to use onTokenReceived from aws-amplify/push-notification for implementing push-notifications on Mobile using react-native

 const myTokenReceivedHandler = (token) => {
  console.log("Push token received in Dashboard:", token);
};

const listener = onTokenReceived(myTokenReceivedHandler);
  return () => listener.remove();
},  []);

But this never gets executed,and I donn receive any token . I am using Firebase-messaging/app package to get token and the using identifyUser from aws-amplify/push-notification to register token to endpoint.

I want to know if anyone else also faced the problem with token generation on aws-amplify?