JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li>
        <label>Category</label>
        <select name="category_1"> 
            <option>CPU</option>
            <option>HDD</option>
        </select>
        <select name="items_1"> 
            <option>Item 1</option>
            <option>Item 2</option>
            <option>Item 3</option>
        </select>
    </li>

</ul>

        <label></label>
        <input type="hidden" name="current_added_products" value="2" />
        <input type="button" class="add_more_product" value ="Add More Product" />

JavaScript

$('.add_more_product').click(function() {
    var $ul = $('ul:last');
    $ul.clone().find('select').attr('name', function(i, cur) {
        return cur.match(/\D+/g).join('') + (Number(cur.match(/\d+/g).join('')) + 1)
    }).end().insertAfter($ul)
})