code: public function checkExtensions($strContent, $strTemplate)
      {
          if ($strTemplate == 'be_main')
          {
              if ( isset($GLOBALS['TL_CONFIG']['dlstatDisableBotdetection']) &&
                  (bool) $GLOBALS['TL_CONFIG']['dlstatDisableBotdetection'] === true )
              {
                  return $strContent;
              }
              
              if (!is_array($_SESSION["TL_INFO"]))
              {
                  $_SESSION["TL_INFO"] = array();
              }
      
              // required extensions
              $arrRequiredExtensions = array(
                      'BotDetection' => 'botdetection'
              );
              
              // check for required extensions
              foreach ($arrRequiredExtensions as $key => $val)
              {
                  if (!in_array($val, \Config::getInstance()->getActiveModules() ))
                  {
                      $_SESSION["TL_INFO"] = array_merge($_SESSION["TL_INFO"], array($val => 'Please install the required extension <strong>' . $key . '</strong> for the extension dlstats.'));
                  }
                  else
                  {
                      if (is_array($_SESSION["TL_INFO"]) && key_exists($val, $_SESSION["TL_INFO"]))
                      {
                          unset($_SESSION["TL_INFO"][$val]);
                      }
                  }
              }
          }
      
          return $strContent;
      }
docs: Hook: Check the required extensions and files for BotStatistics
  
  @param string $strContent
  @param string $strTemplate
  @return string