$user->getName() not returning anything

[edwardsmarkf]

is there any reason why $user->getName() would return empty?
$user->getId() and $user->getEmail() also return empty.

<?php

require 'vendor/autoload.php';  // for php composer

session_start();   // added!

$provider = new Riskio\OAuth2\Client\Provider\Auth0([
        'region'                => Riskio\OAuth2\Client\Provider\Auth0::REGION_US,
        'account'               => 'deXXXXXXm',
        'clientId'              => '0XXXXXXXXXXXXXXXXXXXX4',
        'clientSecret'          => 'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXn',
        'redirectUri'  => 'https://MYDOMAIN.com/auth0/auth0.php'
]);

if (!isset($_GET['code'])) {

    // If we don't have an authorization code then get one
    $authUrl = $provider->getAuthorizationUrl();
    $_SESSION['oauth2state'] = $provider->getState(); //$_SESSION['oauth2state'] = $provider->state;
    header('Location: ' . $authUrl);
    exit;

// Check given state against previously stored one to mitigate CSRF attack
} elseif (empty($_GET['state']) || ($_GET['state'] !== $_SESSION['oauth2state'])) {
    unset($_SESSION['oauth2state']);
    exit('Invalid state');

} else {
    // Try to get an access token (using the authorization code grant)
    $token = $provider->getAccessToken('authorization_code', [
        'code' => $_GET['code']
    ]);

    // Optional: Now you have a token you can look up a users profile data
    try {
        // We got an access token, let's now get the user's details
        $user = $provider->getResourceOwner($token);

        // Use these details to create a new profile
        printf('Hello %s!', $user->getName());

    } catch (Exception $e) {

        // Failed to get user details
        exit('Oh dear...');
    }
    // Use this to interact with an API on the users behalf
    echo $token->getToken();