JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.0/css/bootstrap.min.css">
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.0/js/bootstrap.min.js"></script>
<div class="form-group file-upload-wrapper">
    <input id="the-file" type="file" name="name" onchange="this.handleFile" />    
    <label class="custom-file-label" for="the-file">Choose a file</label>                        
</div>

JavaScript

function handleFile() { 		
    console.log(this.files[0]);         
}