JSFiddle - React, Tailwind, and code Playground

HTML

<script>
    function writeSlowly(text, timer) {
        var L= text.length;
        var st = "";
        var delay = 0;
        for (var i = 0; i < L; i += 1) {
            st += text[i];
            delay += timer
            setTimeout(writer(st), delay);
            if(i === L -1) {
                setTimeout(done, delay);
            }
        };
    }
    
    function writer(toWrite) {
        return function() {
            document.getElementById("st").innerHTML = toWrite;
        }
    }
    
    function done() {
        document.getElementById("st").innerHTML += ' DONE!';
    }

</script>
<body>
<p id="st"></p>
<script>
    writeSlowly("This pages takes a while to load", 200);
</script>
</body>