JSFiddle - React, Tailwind, and code Playground

HTML

<div id="class-1" class="classes">
    <input type="text" id="name-class-1" />
    <input type="text" id="number-class-1" />
    <input type="text" id="book-class-1" />
</div>

<input type="button" id="add" value="add"/>

JavaScript

$("#add").click(function (e) {
    var amount = $('div.classes').length;
    var new_amount = amount + 1;
    var cloned_div = $('#class-' + amount);
    $(cloned_div).clone().attr('id', 'class-' + new_amount).insertAfter('#class-' + amount);
});