Gamepad API Example
Source code example from https://www.bleepingcomputer.com/news/google/google-chrome-getting-support-for-nintendo-switch-gamepads/
HTML
<html>
<head>
<title>Gamepad Test</title>
</head>
<body>
<h2>Gamepad Information</h2>
<p>Gamepad Type: <span id="gamepad_name"></span></p>
</body>
</html>
JavaScript
window.addEventListener("gamepadconnected", function(e) {
var gamepad = navigator.getGamepads()[0];
document.getElementById("gamepad_name").innerHTML = gamepad.id;
});