@isset($exportar)
    @php    
        echo pack("CCC",0xef,0xbb,0xbf); // BOM para UTF-8 en Excel
        header("Cache-Control: maxage=1");
        header("Pragma: public");
        header('Content-type: application/vnd.ms-excel');
        header("Content-Disposition: attachment; filename=Reporte_IVA_" . ($fi ?? '') . "_a_" . ($ff ?? '') . ".xls");
        header("Pragma: no-cache");
        header("Expires: 0");    
    @endphp
@endisset

@include('contabilidad.exportar.formaIvas')