Tags will not diplay about typewriterjs HOT 5 CLOSED

Js File
var app = document.getElementById('brand');

var typewriter = new Typewriter(app, {
    loop: true
});

typewriter.typeString('My name is <br> Aditya Modi')
    .pauseFor(2000)
    .deleteAll()
    .typeString('and this is <br> my Portfolio')
    .pauseFor(2000)
    .deleteAll()
    .typeString("so welcome to")
    .pauseFor(2000)
    .deleteAll()
    .typeString("Aditya Modi")
    .pauseFor(2000)
    .deleteChars(3)
    .typeString(".")
    .start()

Html
<section id= brand-background>
            <h1 id=brand>Aditya M.</h1>
</section>

</body>
<script src="js/core.js"></script>
<script src="js/script.js"></script>
</html>