$step = 1;
$height = 50;//не помню точно, надо подрегулировать будет
$barcode = 'fm00000000705';//example

function generatePdf($html, $barcode, $type = 'svg' ) {

    $mpdf = new \Mpdf\Mpdf([
    'mode' => 'utf-8',
    'format' => [20, 30],
    'orientation' => 'L',
    'setAutoTopMargin' => 'stretch',
    'autoMarginPadding' => 0,
    'bleedMargin' => 0,
    'crossMarkMargin' => 0,
    'cropMarkMargin' => 0,
    'nonPrintMargin' => 0,
    'margBuffer' => 0,
    'collapseBlockMargins' => false,
    'margin_left' => 0,
'margin_right' => 0,
'margin_top' => 0,
'margin_bottom' => 0,
'margin_header' => 0,
'margin_footer' => 0
]);
  if($type != 'svg') $mpdf->img_dpi = 203;
  $mpdf->WriteHTML($html);
  //save the file put which location you need folder/filname
  $mpdf->Output(DIR_BARCODE_IMG.$barcode."_".$type.".pdf", 'F');

}
$generator = new Picqer\Barcode\BarcodeGeneratorPNG();

generatePdf('<div style="margin-left: 6mm; width: 100%; "><img src="data:image/png;base64,' . base64_encode($generator->getBarcode($barcode, $generator::TYPE_CODE_128, $step, $height)) . '"></div><div style="font-size: 2.4mm; width: 100%; text-align: center;">'.$barcode.'</div>', $barcode, 'png');