JSFiddle - React, Tailwind, and code Playground

HTML

<div id="apnd1"></div>
<button type="button" id="btn11">Add product</button>

JavaScript

$(document).ready(function(){
        $("#btn11").click(function(){
            var nw="<div class='product_input'><input type='text'/><br/>";
            nw+="<button type='button' class='btn12'>Add category</button>";
            nw+="</div>";
            $("#apnd1").append(nw);

            
        });
    $("#apnd1").on("click",".btn12",function(){
                alert("jhfj");
            });
});