JSFiddle - React, Tailwind, and code Playground

HTML

<a href="#" id="user_button">click</a>
<div id="hello">abc</div>

CSS

.hello{
    height:100px;
    width:100px;
  
    background-color:#000;
}
.active{
    background-color:#C00;
}

JavaScript

jQuery.fn.make_me_red = function() {
    alert($(this).attr('id'));
    $(this).siblings("#hello").toggle();
}
    $("#user_button").click(function(){
    //$(this).siblings(".hello").make_me_red(); 
    $(this).make_me_red(); 
    $(this).addClass("active");
    });