topnotch_ordersystem/app/Http/Controllers/InvoiceController.php

<?php

namespace App\Http\Controllers;

use App\Models\Invoice;
use Spatie\Browsershot\Browsershot;
use Spatie\LaravelPdf\Facades\Pdf;

class InvoiceController extends Controller
{
    public function pdf(int $id)
    {
        $invoice = Invoice::find($id);

        $firstOrderPo = $invoice->orders()->first()->customer_po ?? '';
        $firstOrderPo = preg_replace('/[\\\\\/:*?"<>|]/', '', $firstOrderPo); // Remove invalid characters
        $firstOrderPo = str_replace(' ', '-', $firstOrderPo);

        $url = strtolower($invoice->internal_id.'-'.$invoice->customer->company_name.'-'.$firstOrderPo.'.pdf');

        Pdf::view('pdf.invoice', ['invoice' => $invoice])
            ->withBrowsershot(function (Browsershot $browsershot) {
                $browsershot->noSandbox();
            })
            ->margins(8, 8, 15, 8)
            ->footerView('pdf.invoice-footer', ['invoice' => $invoice])
            ->save($url);

        return redirect($url);
    }
}