JSFiddle - React, Tailwind, and code Playground

HTML

<DOCTYPE html>
<html>
    <head>
        <title>KeyDown() Failure</title>
    </head>
    <body>
        <h1>KeyDown() Failure</h1>
        <p>Current Keys: <span class="keys"></span></p>
    </body>
</html>

JavaScript

/*!
 * Extracted and modified from Red Locomotive Controls Module
 *
 * This module has been stripped down an modified to work 
 * without Red Locomotive's loader system.
 *
 * http://robertwhurst.github.com/Red-Locomtive/
 *
 * Copyright 2011, Robert William Hurst
 * Licenced under the BSD License.
 * See license.txt at the url above.
 */

jQuery(function () { 
    
    Module = (function() {

        var keys = {
                "backspace": 8,
                "tab": 9,
                "enter": 13,
                "shift": 16,
                "ctrl": 17,
                "alt": 18,
                "pause": 19, "break": 19,
                "capslock": 20,
                "escape": 27, "esc": 27,
                "pageup": 33,
                "pagedown": 34,
                "end": 35,
                "home": 36,
                "left": 37,
                "up": 38,
                "right": 39,
                "down": 40,
                "insert": 45,
                "delete": 46,
                "0": 48, "1": 49, "2": 50, "3": 51, "4": 52, "5": 53, "6": 54, "7": 55, "8": 56, "9": 57,
                "a": 65, "b": 66, "c": 67, "d": 68, "e": 69, "f": 70, "g": 71, "h": 72, "i": 73, "j": 74, "k": 75, "l": 76, "m": 77, "n": 78, "o": 79, "p": 80, "q": 81, "r": 82, "s": 83, "t": 84, "u": 85, "v": 86, "w": 87, "x": 88, "y": 89, "z": 90,
                "meta": 91, "command": 91, "windows": 91, "win": 91,
                "_91": 92,
                "select": 93,
                "num0": 96, "num1": 97, "num2": 98, "num3": 99, "num4": 100, "num5": 101, "num6": 102, "num7": 103, "num8": 104, "num9": 105,
                "multiply": 106,
                "add": 107,
                "subtract": 109,
                "decimal": 110,
                "divide": 111,
                "f1": 112, "f2": 113, "f3": 114, "f4": 115, "f5": 116, "f6": 117, "f7": 118, "f8": 119, "f9": 120, "f10": 121, "f11": 122, "f12": 123,
                "numlock": 144, "num": 144,
               ...