Call to undefined function save_token_to_storage()

Hey all, rookie here when it comes to the Infusionsoft APIs. I am working on writing a set of PHP scripts, initially just to authorize and do a simple read from the database to show proof of function. I am getting caught on authorization and the proper syntax for the query. Can someone help me understand what sections of code I am missing and have incorrect here?

Initial page, index.php

  echo "Session ID Variable Found </br>";

ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);

require_once '/Applications/MAMP/htdocs/vendor/autoload.php';

$infusionsoft = new \Infusionsoft\Infusionsoft(array(
	'clientId'     => 'EQw5ZqUe(PARTIALLYREMOVED)',
	'clientSecret' => 'b5K(PARTIALLYREMOVED)',

	'redirectUri'  => 'http://localhost:8888/keap/index.php',

// If the serialized token is available in the session storage, we tell the SDK
// to use that token for subsequent requests.
if (isset($_SESSION['token'])) {

// If we are returning from Infusionsoft we need to exchange the code for an
// access token.
if (isset($_GET['code']) and !$infusionsoft->getToken()) {

// If we are returning from Infusionsoft we need to exchange the code for an
if ($infusionsoft->getToken()) {
    $_SESSION['token'] = serialize($infusionsoft->getToken());
     echo "<br> Confirmed Token </br>";
} else {
    echo '<a href="' . $infusionsoft->getAuthorizationUrl() . '" target="_blank" >Click here to authorize </a> </br>';

echo "CheckPoint #1 </br>";

$url = '';
$data = file_get_contents($url); // put the contents of the file into a variable
$contacts = json_decode($data); // decode the JSON feed

echo $contacts[0]->name;

foreach ($contacts as $contact) {
	echo $contact->name . '<br>';

echo "End of Test";


Webpage produced:

Session ID Variable Found

Confirmed Token
CheckPoint #1

Warning : file_get_contents( Failed to open stream: HTTP request failed! HTTP/1.1 401 Unauthorized in /Applications/MAMP/htdocs/keap/KEAP.PHP on line 45

Warning : Trying to access array offset on value of type null in /Applications/MAMP/htdocs/keap/KEAP.PHP on line 48

Warning : Attempt to read property “name” on null in /Applications/MAMP/htdocs/keap/KEAP.PHP on line 48

Warning : foreach() argument must be of type array|object, null given in /Applications/MAMP/htdocs/keap/KEAP.PHP on line 50
End of Test