JSFiddle - React, Tailwind, and code Playground

HTML

<input id="check" type="checkbox"/>
<input id="btn1" type="button" value="enable" />
<input id="btn2" type="button" value="disable" />

JavaScript

function enable() {
    var x = document.getElementById("check");
    alert(x.getAttribute("disabled"));
    x.setAttribute("disabled", "false");
    alert(x.getAttribute("disabled"));
}

function disable() {
    var x = document.getElementById("check");
    alert(x.getAttribute("disabled"));
    x.setAttribute("disabled", "true");
    alert(x.getAttribute("disabled"));
}
document.getElementById("btn1").addEventListener("click", enable);
document.getElementById("btn2").addEventListener("click", disable);