Format string number with commas and two decimals in jQuery

<input id="txtNumber" type="text" value="1200900,56" />
<input id="btnSubmit" type="button" value="Submit" />
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.7.1/jquery.min.js"></script>
<script type="text/javascript">
    $(function () {
        $("#btnSubmit").click(function () {
            var parts = $("#txtNumber").val().split(',');
            parts[0] = parseFloat(parts[0].replace(/\D/g, "")).toLocaleString('de-DE');
            $("#txtNumber").val(parts[0] + (parts[1] ? "," + parts[1] : ""));
        });
    });
</script>