Laravel Broadcast on demand

on documentation laravel about notification on demand it's only have example for mail,slack and nexmo so how to send notification via broadcast use on demand. https://laravel.com/docs/5.8/notifications

that example for mail

Notification::route('mail', 'taylor@example.com')
        ->route('nexmo', '5555555555')
        ->route('slack', 'https://hooks.slack.com/services/...')
        ->notify(new InvoicePaid($invoice));

or how to send notification broadcast without Elequent.

via Chebli Mohamed