/**
  * Ajax activation
  *
  * @since     1.3.1
  */
 public function ajax_activation()
 {
     // keys
     $key = $_POST['key'];
     $type = $_POST['type'];
     $licence = new cpac_licence($type);
     // update key
     if ($key == 'remove') {
         $licence->remove_license_key();
     } elseif ($licence->check_remote_key($key)) {
         // set key
         $licence->set_license_key($key);
         // returned masked key
         echo json_encode($licence->get_masked_license_key());
     }
     exit;
 }