<html>
<head>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.7.1/jquery.min.js" type="text/javascript"></script>
</head>
<script type="text/javascript">
function add() {
$('.todo-table').append('<tr><td class="1"><input type="text" /></td></tr>');
}
</script>
<body>
<h1 class="first">TODO app</h1>
<table class="todo-table">
</table>
<button onclick="add()" >
Add
</button>
</body>
</html>