joomla make a ajax request for another php file

Question

Excuse me for my English. I'm a newbie in joomla. I make a phone book component and i wanna add a Ajax pagination. I've got Jquery function load_data where i put a url to my php page. And this is where i block.

(Updated)

// default.php
            // No direct access to this file
            defined('_JEXEC') or die('Restricted access');

            JHtml::_('stylesheet', JUri::root() . 'media/com_annuaire/css/annuaire.css');  // For CSS files
            JHtml::_('script', "//ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"); 
            JHtml::_('script', JUri::root() . 'media/com_annuaire/js/annuaire.js'); 



            $item = $this->item->loadObject();
            ?>

            <div id="background-annuaire" style="background-image: url('<?php echo $item->background; ?>');">
                <div id="background-bloc">
                    <div id="bloc-annuaire">

                    </div>
                </div>
            </div>
            <script>  
             $(document).ready(function(){  
                  load_data();  
                  function load_data(page)  
                  {  
                       $.ajax({  
                            url:"/components/com_annuaire/views/annuaire/tmpl/pagination.php",  
                            method:"POST",  
                            data:{page:page},  
                            success:function(data){  
                                 $('#bloc-annuaire').html(data);  
                            }  
                       })  
                  }  
                  $(document).on('click', '.pagination_link', function(){  
                       var page = $(this).attr("id");  
                       load_data(page);  
                  });  
             });  
             </script>  


     //pagination.php  

    defined('_JEXEC') or die('Restricted access');



     $record_per_page = 5;  
     $page = '';  
     $output = '';  
     if(isset($_POST["page"]))  
     {  
          $page = $_POST["page"];  
     }  
     else  
     {  
          $page = 1;  
     }  

     $start_from = ($page - 1)*$record_per_page;  
     echo "1";

          $jinput = JFactory::getApplication()->input;
          $id     = $jinput->get('id', 1, 'INT');

          $db    = JFactory::getDbo();
          $query = $db->getQuery(true);
          $query->select('s.id as id,s.title,#__annucategories.title as category,annucatid,annuid,s.desc,s.address,s.numberphone,s.mail,s.city,s.place,#__annuairespoissy.background as background')
              ->from('#__servicespoissy AS s')
              ->leftJoin('#__annucategories on annucatid=#__annucategories.id')
              ->leftJoin('#__annuairespoissy on annuid=#__annuairespoissy.id')
              ->where('s.published = 1 AND annuid=' . (int)$id);
          $db->setQuery((string)$query,$record_per_page,$start_from);
          $items = $db->loadObjectList(); 
          echo "2";

        foreach ($items as $row) : ?>
            <div class="bloc-service">
              <div class="category-annuaire"><?php echo $row->category; ?></div>
              <div class="category-title"><?php echo $row->title; ?></div>
              <span>En savoir plus</span>
              <div class="informations">
                <div class="category-desc"><?php echo $row->desc; ?></div>

                <div class="category-place"><img src ="/media/com_annuaire/images/place.png" alt="ico" style="float:left; padding-right: 5px;"><p><strong><?php echo $row->place; ?> - <?php echo $row->address; ?> - <?php echo $row->city; ?></strong></p></div>
                <div class="category-numberphone"><img src ="/media/com_annuaire/images/tel.png" alt="ico" style="float:left; padding-right: 5px;"><p><strong><?php echo $row->numberphone; ?></strong></p></div>
                <div class="category-mail"><img src ="/media/com_annuaire/images/mail.png" alt="ico" style="float:left; padding-right: 5px;"><p><strong><?php echo $row->mail; ?></strong></p></div>
              </div>
            </div>
          <?php endforeach; ?>

    <?
      echo "string";
     $total_records = $db->loadRowList();
     $total_pages = ceil($total_records/$record_per_page);  
     for($i=1; $i<=$total_pages; $i++)  
     {  
          $output .= "<span class='pagination_link' style='cursor:pointer; padding:6px; border:1px solid #ccc;' id='".$i."'>".$i."</span>";  
     }  
     $output .= '</div><br /><br />';  
     echo $output;  
     ?>  

As result, i've got 'Restricted access', so i try to remove 'defined('_JEXEC') or die('Restricted access');' from pagination.php, but my browser returns : "Failed to load resource: the server responded with a status of 500". I know i do something wrong but i don't know what. Someone to help me pls ? All my files are in the same directory.