JSFiddle - React, Tailwind, and code Playground

HTML

<button onclick="loadJavascript()" id="myButton">Load js</button>

JavaScript

function loadJavascript(){
	var myButton = document.getElementById('myButton');
	myButton.disabled = true;
	var jsElt = document.createElement("script");
	document.head.appendChild(jsElt);
	jsElt.onload = function() { 
        alert('see button it is disabled');
		myButton.disabled = false;
        
		//mylib.myfunction(); call your function here
	}
	//here your src for js file, this is just testing purpose
	jsElt.src = "http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js";
}