JSFiddle - React, Tailwind, and code Playground

HTML

<img src="https://cs9.pikabu.ru/post_img/2020/10/24/5/1603519896153419851.jpg">

CSS

img {
  border: 1px solid #000000;
  opacity: 0.3
}

img.active {
  opacity: 1;
}

JavaScript

document.querySelectorAll('img').forEach(img => {
	img.addEventListener('click', (e) => {
  	e.target.classList.toggle('active')
  })
})