JSFiddle - React, Tailwind, and code Playground
HTML
<img id='image' src='http://www.pinaldave.com/bimg/ilovesamples.jpg' />
JavaScript
function getXY(event) {
var x = event.pageX - this.offsetLeft;
var y = event.pageY - this.offsetTop;
alert('(' + x + ',' + y + ')');
// Use AJAX to send data to server.
}
document.getElementById('image').addEventListener('click', getXY);