如何使用JQuery pdfHtml5使整个DataTable在pdf中居中？

<script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
<link rel="stylesheet" type="text/css" href="https://cdn.datatables.net/v/dt/dt-1.11.4/datatables.min.css" />
<script type="text/javascript" src="https://cdn.datatables.net/v/dt/dt-1.11.4/datatables.min.js"></script>

<script src="https://cdnjs.cloudflare.com/ajax/libs/pdfmake/0.1.68/pdfmake.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/pdfmake/0.1.68/vfs_fonts.js"></script>
<script src="https://cdn.datatables.net/v/dt/dt-1.11.4/plugins/pdfHtml5/pdfHtml5.min.js"></script>

<table id="example" class="display" style="width:100%">
    <thead>
        <tr>
            <th>Name</th>
            <th>Position</th>
            <th>Office</th>
            <th>Age</th>
            <th>Start date</th>
            <th>Salary</th>
        </tr>
    </thead>
    <tbody>
        <!-- 在此处添加数据 -->
    </tbody>
</table>

$(document).ready(function() {
    $('#example').DataTable({
        dom: 'Bfrtip',
        buttons: [
            {
                extend: 'pdfHtml5',
                text: '导出PDF',
                orientation: 'portrait',
                pageSize: 'A4',
                customize: function (doc) {
                    // 在此处添加自定义样式和选项
                }
            }
        ]
    });
});

customize: function (doc) {
    var pageSize = doc.pageSize;
    var margin = doc.pageMargins;

    // 设置页面大小
    doc.pageSize = {
        width: pageSize.width,
        height: pageSize.height,
        margin: '0 auto'
    };

    // 设置页边距
    doc.pageMargins = {
        top: 'auto',
        bottom: 'auto',
        left: margin.left,
        right: margin.right
    };
}