JSFiddle - React, Tailwind, and code Playground

HTML

<ol id="wybrane">
    <li>A</li>
    <li>B</li>
    <li>C</li>
</ol>

<p id="test">CLICK</p>

<p id="ile"></p>

CSS

#test, #wybrane {
    cursor: pointer;
}

JavaScript

$(document).ready(function(){
   
    $("#test").click(function(){
        $("#wybrane").append("<li>TEST</li>");
    });
    
    $("li").click(function(){
        var ile = $("#wybrane li").length;
        $("#ile").text(ile);
    });
    
});