Laravel - Notifications - Generating The Message

To generate a notification with a corresponding Markdown template, you may use the --markdown option of the make:notification Artisan command:

    php artisan make:notification InvoicePaid --markdown=mail.invoice.paid

Like all other mail notifications, notifications that use Markdown templates should define a toMail method on their notification class. However, instead of using the line and action methods to construct the notification, use the markdown method to specify the name of the Markdown template that should be used. An array of data you wish to make available to the template may be passed as the method's second argument:

     * Get the mail representation of the notification.
     * @param  mixed  $notifiable
     * @return \Illuminate\Notifications\Messages\MailMessage
    public function toMail($notifiable)
        $url = url('/invoice/'.$this->invoice->id);
        return (new MailMessage)
                    ->subject('Invoice Paid')
                    ->markdown('mail.invoice.paid', ['url' => $url]);