Pusher on Codeigniter

Hello i am using darkwhispering pusher API on my codeigniter I already replace everything like: 1.application/config/pusher.php <-- i already replaced the values such as keys etc.

2.application/libraries/CI_pusher.php <-- i already included to my autoload $autoload['libraries'] = array('ci_pusher');

3.I already changed the $config['composer_autoload'] = TRUE;

4.I already installed the php-pusher-sdk via composer on my application and it creates vendor folder on my application which includes composer and pusher folders.

This is my PUSHER DETAIL Channel: mis Event: my-event

My php on trigger public function trigger_event() {

    $pusher = $this->ci_pusher->get_pusher();

    // Set message
    $data['message'] = 'This message was sent at ' . date('Y-m-d H:i:s');

    // Send message
    $event = $pusher->trigger('mis', 'my-event', $data);

    if ($event === TRUE)
    {
        echo 'Event triggered successfully!';
    }
    else
    {
        echo 'Ouch, something happend. Could not trigger event.';
    }
}

The problem is the event is not triggering properly it executes 'Ouch, something happend. Could not trigger event.'