invoiceninja/app/Jobs/Invoice/InvoiceNotification.php

<?php

namespace App\Jobs\Invoice;

use App\Models\Invoice;
use App\Repositories\InvoiceRepository;
use Illuminate\Bus\Queueable;
use Illuminate\Contracts\Queue\ShouldQueue;
use Illuminate\Foundation\Bus\Dispatchable;
use Illuminate\Queue\InteractsWithQueue;
use Illuminate\Queue\SerializesModels;

class InvoiceNotification implements ShouldQueue
{
    use Dispatchable, InteractsWithQueue, Queueable, SerializesModels;

    public $invoice;

    /**
     * Create a new job instance.
     *
     * @return void
     */
    public function __construct(Invoice $invoice)
    {

        $this->invoice = $invoice;

    }

    /**
     * Execute the job.
     *
     * 
     * @return void
     */
    public function handle()
    {

        //notification for the invoice.
        //
        //could mean a email, sms, slack, push

    }
}