title: Illuminate\Broadcasting\BroadcastException: auth_key should be a valid app key laravel 5.8
body: <p>I am integration laravel pusher it is working fine on local host but on live server in queue it is giving this error</p>
  <pre><code>Illuminate\Broadcasting\BroadcastException: auth_key should be a valid app key 
  </code></pre>
  <p>env file</p>
  <pre><code>BROADCAST_DRIVER=pusher
  PUSHER_APP_ID=*****
  PUSHER_APP_KEY=****
  PUSHER_APP_SECRET=*****
  PUSHER_APP_CLUSTER=ap2
  </code></pre>
  <p>broadcating.php</p>
  <pre><code>  'pusher' =&gt; [
              'driver' =&gt; 'pusher',
              'key' =&gt; env('PUSHER_APP_KEY'),
              'secret' =&gt; env('PUSHER_APP_SECRET'),
              'app_id' =&gt; env('PUSHER_APP_ID'),
              'options' =&gt; [
                  'cluster' =&gt; 'ap2',
                  'useTLS' =&gt; true,
              ],
          ],
  </code></pre>