Error: Class 'Stripe\Stripe' not found

Fatal error: Uncaught (Status 400) (Request req_jxSfVvPRWqw6XO) No such token: 'tok_1IbQVs2eZvKYlo2CjNsKtjay' thrown in C:\xampp\htdocs\paypage\vendor\stripe\stripe-php\lib\Exception\ApiErrorException.php on line 38

<?php
require_once 'vendor/autoload.php';


$stripe = new \Stripe\StripeClient(
	'sk_test_xxxxxxxxxxxxxxxxxxxxxxxxxx'
  );
//Sanitize POST Array
$POST = filter_var_array($_POST, FILTER_SANITIZE_STRING);

$first_name = $POST['prenom'];
$last_name = $POST['nom'];
$email = $POST['email'];
$token = $POST['stripeToken'];
  $custmer = $stripe->customers->create([
	'email' => $email,
	'description' => 'Grand thef auto 5',
	'source' => $token
	
  ]);
 
  

  $charge = $stripe->charges->create([
	'amount' => 4000,
	'currency' => 'usd',
	'descriptin' => 'Grand Thef Auto V',
	'customer' => $custmer->id
  ]);

  print_r($charger);
?>

<?php
 require_once 'vendor/autoload.php';
 
 \Stripe\Stripe::setApiKey('pk_test_xxxxxxx');

 //Sanitize POST Array
 $POST = filter_var_array($_POST, FILTER_SANITIZE_STRING);

 $first_name = $POST['prenom'];
 $last_name = $POST['nom'];
 $email = $POST['email'];
 $token = $POST['stripeToken'];


 // Create customer in stripe
 $customer = \Stripe\Customer::create(array(
 	"email" => $email,
 	"source" => $token
 ));

 //Charge Customer
 $charge = \Stripe\Charge::create(array(
 	"amount" => 5000,
 	"currency" => "usd",
 	"description" => "Cyberpunk 2077",
 	"customer" => $customer->id
 ));

 print_r($charge);
?>