How to get Error Event message

[JaveedIshaq]

Pusher: {"event":"pusher:error","data":{"code":4001,"message":"App key 022f605af286ca4635bb not in this cluster. Did you forget to specify the cluster?"}}

If the credentials are wrong pusher show the above error and prints in the console, Kindly guide how to get this error

the following bind to pusher-error event does not show any data, Kindly guide thanks

 channel.bind('pusher:error', (data) {
   
      print(data);
     
    });