SATE-EasyReceipt/app/Files/PDF/Receipt/A4Receipt.php

<?php

namespace App\Files\PDF\Receipt;

use App\Files\TmpFile;

class A4Receipt extends TmpFile
{

    protected const DIR = ['receipt_pdf'];

    /**
     * @override
     */
    protected function getFileTypeName(): string
    {
        return "A4Receipt";
    }

    /**
     * @override
     */
    protected function getFileExtension(): string
    {
        return "pdf";
    }
}