MPDF class - Base64 images

Question

good afternoon, I am using a mdpf class to generate the PDF of a file, but when using an image in Base64 inside a <img> model my image did not appear

Function:

    $date = date("dmYHi");
    $mpdf = new mPDF('','A4',0,'',10,5,7,7,6,6,'L');
    $mpdf->charset_in='windows-1252';
    $mpdf->WriteHTML($modelo);
    $mpdf->Output("boletos/orcamentopdf_".$date.$_GET['id'].".pdf");

Can someone tell me a way to fix this or to record the model with the image in the comic book?

Obs.: When I go through the browser everything comes out right and beautiful! Only using this function that!