JSFiddle - React, Tailwind, and code Playground

HTML

<input type="checkbox" class="chbx" />
<button class="btn">Trigger</button>

<div class="output"></div>

JavaScript

var input = document.querySelector('.chbx')
  , button = document.querySelector('.btn')
  , output = document.querySelector('.output');

button.addEventListener('click', function() {
    if (input.checked) input.checked = false;
    else input.checked = true;
});

input.addEventListener('change', function() {
    output.innerHTML += ' changed';
});