http://localhost:8000/broadcasting/auth 404 (Not Found)
Look in config/app.php if you have uncommented
App\Providers\BroadcastServiceProvider::class,
There are two Service Providers with Same name but different namespace in config/app.php
Illuminate\Broadcasting\BroadcastServiceProvider::class,App\Providers\BroadcastServiceProvider::class,
So uncomment both of them. It will work.
Hope your base url is wrong try to hardcore your base url like below
window.Echo = new Echo({ authEndpoint : 'http://*******/public/broadcasting/auth', broadcaster: 'pusher', key: '********', cluster: '***', encrypted: true});