Wordpress Ajax

functions.php

<?php 
/*IS NOT WOOCOMMERCE*/
if ( ! function_exists( 'is_ajax' ) ) {
 /**
  * is_ajax - Returns true when the page is loaded via ajax.
  * @return bool
  */
 function is_ajax() {
  return defined( 'DOING_AJAX' );
 }
}
//FUNCTIONS AJAX
add_action( 'wp_ajax_loadPosts', 'loadPosts');
add_action( 'wp_ajax_nopriv_loadPosts', 'loadPosts');
function loadPosts($paged = 1){
  extract($_POST);
    //show post
    
    if (is_ajax()) {
        exit();
    }
}
//FUNCTIONS VARIABLES JS
function js_variables(){
    $variables = array (
        'ajax_url' => admin_url('admin-ajax.php'),
    );
    echo(
        '<script type="text/javascript">window.wp_data = '.
        json_encode($variables).
        ';</script>'
    );
}
add_action('wp_head','js_variables');

loadPosts.js

$(document).on("click", "#button", function(){
  
  var ajaxcontent = $('.products');
  $.ajax({
          type: 'POST',
          url: window.wp_data.ajax_url,
          data: {
                  action: "loadPosts",
              },
          success: function (html) {
                ajaxcontent.html(html);
          }
   });
  return false;
  
});