你好，我在其他项目中使用了dompdf，它工作得很好，这次我没有生成pdf，load_html函数返回null，我的ide告诉我：

Method 'load_html' is deprecated

下面是我写的代码：

use Dompdf\Dompdf;

    $dompdf = new DOMPDF();

    $dompdf->set_option('isHtml5ParserEnabled', true);

    $html = str_replace(
        array(
            '{{DOCUMENT}}',
            '{{DATE}}',
            '{{TITLE}}',
            '{{USER_FIRSTNAME}}',
            '{{USER_LASTNAME}}',
            '{{SPECIALITY}}',
            '{{DESC}}',
            '{{PATIENT_FIRSTNAME}}',
            '{{PATIENT_LASTNAME}}',
            '{{INVOICE_NUMBER}}',
            '{{PRICE}}',
            '{{PRICE_TTC}}',
            ' class="no-tva"'
        ),
        array(
            'Facture',
            date('d/m/Y'),
            $_SESSION['cabinet_data_user']['infos']['title'],
            substr($_SESSION['cabinet_data_user']['infos']['firstname'], 0, 1).'.',
            $_SESSION['cabinet_data_user']['infos']['lastname'],
            $_SESSION['cabinet_data_user']['infos']['speciality'],
            $_user_desc,
            ucfirst(mb_strtolower($invoice_pdf['firstname'])),
            ucfirst(mb_strtolower($invoice_pdf['lastname'])),
            isset($invoice_pdf['id']) ? $invoice_pdf['id'] : '123456',
            number_format($invoice_pdf['price'], 2, ',', '.'),
            ($invoice_pdf['tva']) ?
                number_format($invoice_pdf['price'] + $invoice_pdf['price'] * $invoice_pdf['tva'], 2, ',', '.') :
                number_format($invoice_pdf['price'], 2, ',', '.'),
            $invoice_pdf['tva'] ? '' : ' class="no-tva"'
        ),
        file_get_contents(BASE.'params/templates/invoice.html')
    );

    unset($_user_desc);

    $dompdf->load_html($html);
    $dompdf->setPaper('A4', 'portrait');
    $dompdf->render();

任何建议都可以帮助，谢谢。