mpdf output generate error Error detected. PDF file generation aborted: Directive ‘allow_url_include’ is deprecated

I am writing a wordpress plugin and creating a function that generates an invoice and sends it by e-mail. There was a problem generating the PDF file. Each attempt to generate a PDF file ends with the error: Error detected. PDF generation aborted: “allow_url_include” directive is deprecated

My code:

 $defaultConfig = (new MpdfConfigConfigVariables())->getDefaults();
    $fontDirs = $defaultConfig['fontDir'];

    $defaultFontConfig = (new MpdfConfigFontVariables())->getDefaults();
    $fontData = $defaultFontConfig['fontdata'];
    try {
        $mpdf = new MpdfMpdf([
            'fontDir' => array_merge($fontDirs, [
                __DIR__ . '/mpdf2/vendor/mpdf/mpdf/ttfonts',
            ]),
            'fontdata' => $fontData + [
                    'roboto' => [
                        'R' => 'Roboto-Regular.ttf',
                        'B' => 'Roboto-Bold.ttf',
                    ]
                ],
            'mode' => 'UTF-8',
            'format' => 'A4',
            'default_font_size' => '12',
            'default_font' => 'roboto',
            'margin_left' => 25,
            'margin_top' => 25,
            'margin_right' => 25,
            'margin_bottom' => 25,
            'debug' => true,
        ]);
        $dir = plugin_dir_path(__DIR__);
        $mpdf->SetDisplayMode('fullwidth');
        $mpdf->WriteHTML($html);
        $mpdf->Output($dir . 'haccp/invoice_pdf/' . $invoice_name, 'F');
    } catch (MpdfMpdfException $e) { // Note: safer fully qualified exception name used for catch
        // Process the exception, log, print etc.
        echo $e->getMessage();
    }

Answer

mPDF is catching an error caused by you setting a allow_url_include INI variable after upgrading to PHP 7.4 – either in ini_set call or in PHP configuration (php.ini file, .htaccess, server configuration).

Remove the allow_url_include setting change or rollback to PHP 7.3 or perhaps disable deprecated warnings.

See https://www.php.net/manual/en/filesystem.configuration.php