title: Fatal error: Class 'Paypal\Api\Payer' not found en sdk Paypal
body: <p>I installed PayPal SDK with composer but my php file CHECKOUT.php the error is:</p>
  
  <blockquote>
    <p>Fatal error: Class 'Paypal\Api\Payer' not found in
    C:\xampp\htdocs\pagos\checkout.php on line 23</p>
  </blockquote>
  
  <p>checkout.php:</p>
  
  <pre><code>&lt;?php
  require ("start.php");
  
  use Paypal\Api\Payer;
  use Paypal\Api\Item;
  
  $payer = new Payer();
  $payer-&gt;setPaymentMethod("paypal");
  
  $item = new Item();
  $item-&gt;setName($descripcion)
      -&gt;setCurrency('MXN')
      -&gt;setQuantity(1)
      -&gt;setPrice($precio);
  $itemList = new ItemList();
  $itemList-&gt;setItems([$item]);
  </code></pre>
  
  <p>start.php</p>
  
  <pre><code>&lt;?php
  // 1. Autoload the SDK Package. This will include all the files and classes to your autoloader
  // Used for composer based installation
  require __DIR__  . '/vendor/autoload.php';
  // Use below for direct download installation
  // require __DIR__  . '/PayPal-PHP-SDK/autoload.php';  
  
  $apiContext = new \PayPal\Rest\ApiContext(
      new \PayPal\Auth\OAuthTokenCredential(
          'ashdjkhaskdjhalksdfjhaglskjdfhlasdfasdfsdfgh',     // ClientID
          'ejkhsdkjhakjdhakjshdkjashdkjashdkjaskjdhaskjh'      // ClientSecret
      )
  );
  
  $apiContext-&gt;setConfig([
   'mode'=&gt;'sandbox',
   'http.ConnectionTimeOut'=&gt;30,
   'log.LogEnabled'=&gt;false,
   'log.FileName'=&gt;'',
   'log.LogLevel'=&gt;'FINE',
   'validation.level'=&gt;'log'
  ]);
  </code></pre>