JSFiddle - React, Tailwind, and code Playground

HTML

<div class="card">
      <div class="card-body">
        <h5 class="card-title">pikachu</h5>
        <p class="card-text">lorem ipsum</p>
        <button id="btn" onClick="showSkills(this)" class="btn btn-primary">Skills</button>
      </div>
      <div id='text' class='skills hidden'>
       <p>skill skill</p>
      </div>
 </div>

CSS

.hidden{
  background-color:blue;
}

JavaScript

function showSkills(_this) {

    _this.classList.toggle('hidden');
   
}