Save dynamically created table content in excel file using SheetJS

Question

I add rows into html table dynamically and I want to save the table content into xlsx file using SheetJs. The generated file is empty. Is somehow possible to do this in this case when table content was added this way? I also tried to add the rows rigth before creating the xlsx file..

<!DOCTYPE html>
<html>

<head>
    <script src="https://code.jquery.com/jquery-2.1.4.js"
        integrity="sha256-siFczlgw4jULnUICcdm9gjQPZkw/YPDqhQ9+nAOScE4=" crossorigin="anonymous"></script>
    <script type="text/javascript"
        src="https://cdnjs.cloudflare.com/ajax/libs/amcharts/3.21.15/plugins/export/libs/FileSaver.js/FileSaver.min.js"></script>
    <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/xlsx/0.15.6/xlsx.full.min.js"></script>

    <style>
        table,
        td {
            border: 1px solid black;
        }
    </style>
</head>

<body>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/xlsx/0.10.3/xlsx.full.min.js">
    </script>

    <p>Click the button to add a new row at the first position of the
        table and then add cells and content</p>

    <table id="myTable">
        <TR>
        </TR>
    </table>
    <button type="button" id="first" onclick="First('myTable')">Principal</button>
    <button id="button-a">Create Excel</button>
    <script>
        function First(tableID) {
            let table = document.getElementById(tableID)
            table.innerHTML = "<tr>first</tr>";
        }

    </script>

    <script>
        var wb = XLSX.utils.table_to_book(document.getElementById('myTable'), { sheet: "Sheet JS" });
        var wbout = XLSX.write(wb, { bookType: 'xlsx', bookSST: true, type: 'binary' });
        function s2ab(s) {
            var buf = new ArrayBuffer(s.length);
            var view = new Uint8Array(buf);
            for (var i = 0; i < s.length; i++) view[i] = s.charCodeAt(i) & 0xFF;
            return buf;
        }
        $("#button-a").click(function () {
            saveAs(new Blob([s2ab(wbout)], { type: "application/octet-stream" }), 'test.xlsx');
        });
    </script>
</body>

</html>