JSFiddle - React, Tailwind, and code Playground

HTML

<table>
    <tr>
        <button id="btnAdd">Add</button>
    </tr>

    <tr>
        <td>
            <select name="ddl_1" id="ddl_1" name="ddl_1">
                <option value="1">One</option>
                <option value="2">Two</option>
                <option value="3">Three</option>
            </select>
        </td>
        <td>
            <input type="text" id="txt_1" name="txt_1" />
        </td>
    </tr>

    

</table>

JavaScript

var counter = 1;

$("#btnAdd").click(function() {
     counter++
    $('table').find("tr:eq(1)").clone().appendTo("table").find('select')
               .attr({
                   'name': 'ddl_' + counter,
                   'id'   : 'ddl_' + counter
               })
               .closest('td').next('td').find('input')
               .attr({
                   'name': 'ddl_' + counter,
                   'id'   : 'ddl_' + counter
               })
});