JSFiddle - React, Tailwind, and code Playground

HTML

<audio id="mytrack" controls>
        <source src="https://archive.org/download/testmp3testfile/mpthreetest.mp3" type="audio/mp3">
</audio>

JavaScript

mytrack = document.getElementById('mytrack');
mytrack.addEventListener("loadeddata", function() {
    alert(this.duration);
});