How to add custom notification channel in Laravel 5.3

I have an Issue with getting a laravel custom notification channel to work. I have the following git to implement:

laravel-notification-channels/webhook

When I install it as per instructions, create a new notofication, call this notification on my route I get the following error:

InvalidArgumentException in Manager.php line 90: Driver [NotificationChannels\Webhook\WebhookChannel] not supported.

I noticed that some packeges are registering as Service providers, this one does not however.

What it the problem here please? What Am I missing?

via Chebli Mohamed