JSFiddle - React, Tailwind, and code Playground
HTML
<form>
<label>
<input type="checkbox" name="hey" value="hejsa" /> Hey
</label>
</form>
JavaScript
const $form = document.querySelector("form");
const $input = document.querySelector("input");
$input.addEventListener("change", (e) => {
console.log("value", new FormData(document.querySelector('form')));
})