title: Laravel 5.4 Call to undefined function App\iconv()
body: <p>I have uploaded my project to a server, and now it is giving me problems, which can be ?, in local the project runs perfectly. this is the code of my function</p>
  
  <pre><code>&lt;?php
  
  namespace App;
  
  use Illuminate\Database\Eloquent\Model;
  
  class Gateway extends Model
  {
       function _doPost($query) {
          $ch = curl_init();
          curl_setopt($ch, CURLOPT_URL, "https://secure.nmi.com/api/transact.php");
          curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 30);
          curl_setopt($ch, CURLOPT_TIMEOUT, 30);
          curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
          curl_setopt($ch, CURLOPT_HEADER, 0);
          curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
  
          curl_setopt($ch, CURLOPT_POSTFIELDS, $query);
          curl_setopt($ch, CURLOPT_POST, 1);
  
          if (!($data = curl_exec($ch))) {
              return ERROR;
          }
          $wm_string = iconv("windows-1251", "UTF-8", $data);
          parse_str(urldecode($wm_string), $result);
          $data=json_encode($result, JSON_UNESCAPED_UNICODE);
          curl_close($ch);
          unset($ch);
  
          $this-&gt;datos=$data;
          return $this-&gt;datos;
        } 
         }
  </code></pre>
  
  <p>the error is</p>
  
  <p><strong>Call to undefined function App\iconv()</strong>
  in this line</p>
  
  <pre><code>    $wm_string = iconv("windows-1251", "UTF-8", $data);
  </code></pre>
  
  <p>can be this a server problem? or maybe I must to download some package to my project?</p>