Laravel via - ['nexmo'] did not work

Hi I am making laravel SMS Notification by using Nexmo API.

I have integrated nexmo as per given laravel documentation and as well as given in github.

My below code is working fine.

     Nexmo::message()->send([
        'to'   => 'xxxxxxx',
        'from' => 'xxxxxxx',
        'text' => 'Using the facade to send a message.'
     ]);

the above code is sending the SMS.

I need this to integrate as a Notification. but unfortunately return ['nexmo'] did not work. It did not hit to toNexmo($notifiable) method in the notification.

Can anyone help me.

Thanks

via Chebli Mohamed