JSFiddle - React, Tailwind, and code Playground

HTML

<form name="foo">
    <input name="bar" type="checkbox">
    <input name="baz" type="text"/>
</form>

JavaScript

//document.forms['foo'].bar.checked=false;
setTimeout(function() {
    document.forms['foo'].bar.setAttribute("checked", "true");
}, 5000);

//document.forms['foo'].baz.value = 'prop value';
setTimeout(function() {
    document.forms['foo'].baz.setAttribute("value", "attr value");
}, 5000);