JSFiddle - React, Tailwind, and code Playground

HTML

<form>
<input id=a>
<input type=submit>
</form>
<button id=1>Set
<button id=2>Remove

JavaScript

a = $('#a');

document.getElementById('1').onclick = function(){
	a.attr('required', 'required');
}
document.getElementById('2').onclick = function(){
	a.removeAttr('required');
}