Laravel - Notifications - Mailables And On Demand Notifications

If you are sending an on-demand notification, the $notifiable instance given to the toMail method will be an instance of Illuminate\Notifications\AnonymousNotifiable, which offers a routeNotificationFor method that may be used to retrieve the email address the on-demand notification should be sent to:

    use App\Mail\InvoicePaid as InvoicePaidMailable;
    use Illuminate\Notifications\AnonymousNotifiable;
     * Get the mail representation of the notification.
     * @param  mixed  $notifiable
     * @return Mailable
    public function toMail($notifiable)
        $address = $notifiable instanceof AnonymousNotifiable
                ? $notifiable->routeNotificationFor('mail')
                : $notifiable->email;
        return (new InvoicePaidMailable($this->invoice))