JSFiddle - React, Tailwind, and code Playground

HTML

<input type="file" id="files"/>
<textarea id="myText"></textarea>

JavaScript

document.getElementById('files').addEventListener('change', CopyMe, false);
function CopyMe(evt) {
    var file = evt.target.files[0];
    if (file) {
        var reader = new FileReader();
        reader.readAsDataURL(file)
        }
    };