<?php

session_start();

$steam = new SteamAuth();

$steam->setReturnUrl('example.php');

if($steam->verifyLogin()) {

$steam->setSteamKey('API_KEY'); //YOU CAN GET THIS HERE https://steamcommunity.com/dev/apikey

$user = $steam->loadProfile();

$_SESSION['user'] = $user->personaname;

echo '<pre>'.print_r($user,true).'</pre>';

}else if(!isset($_SESSION['user']))

echo $steam->getAuthButton();

if(isset($_SESSION['user']))

echo 'Welcome, '.$_SESSION['user'].'!';