JSFiddle - React, Tailwind, and code Playground

HTML

<p><input id="input1" type="text" value="1"></p>
<p><input id="input2" type="text" value="2"></p>
<p><input id="input3" type="text" value="3" onkeyup="kbHandler(event)"></p>

JavaScript

function kbHandler(e) {
    if (e.keyCode != 13) alert(e.keyCode);
}

window.onload = function() {
    document.getElementById('input1').onkeyup = kbHandler;
    document.getElementById('input2').onkeyup = function(e) {
        kbHandler(e);
    };
}