JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/knockout/3.5.1/knockout-latest.js"></script>
<button data-bind="click: clicou">botĂŁo</button>

JavaScript

var viewModel = {
  clicou : function() {
    alert("clicou");
  }
};
ko.applyBindings(viewModel);