JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
  <li class="list-group-item">Cras justo odio</li>
  <li class="list-group-item">Dapibus ac facilisis in</li>
  <li class="list-group-item">Morbi leo risus</li>
</ul>

CSS

.list-group-item {
  cursor: pointer;
}

JavaScript

var btn = document.querySelectorAll('.list-group-item');

for (i = 0; i < btn.length; i++) {
  btn[i].addEventListener('click', function() {
    this.style.backgroundColor = 'red';
  });
}