4. Khởi tạo chạy partials/list_ct.php (ok)

C:\xampp\htdocs\test\wp-content\plugins\plugin-name\admin\class-wpf-admin_ct.php

<?php
class WPF_Admin_CT {
  private $plugin_name;
  private $version;
  public function __construct($plugin_name, $version) {
    $this->plugin_name = $plugin_name;
    $this->version     = $version;
    add_action('admin_menu', array($this, 'add_plugin_admin_menu_ct'));
  }
  public function add_plugin_admin_menu_ct() {
    add_menu_page(
      __('Product Filters', 'wpf_ct'), __('Lionel Product Filters', 'wpf_ct'), 'manage_options', 'wpf_search_ct', array($this, 'display_search_forms_ct'), 'dashicons-welcome-write-blog', '50'
    );
    $this->plugin_about_page();
  }
  public function plugin_about_page() {
    add_submenu_page(
      'wpf_search_ct',
      __('About', 'wpf'),
      __('About', 'wpf'),
      'manage_options',
      'wpf_about',
      array($this, 'create_about_page')
    );
  }
  public function display_search_forms_ct() {
    include_once( 'partials/list_ct.php' );
  }
}
?>

C:\xampp\htdocs\test\wp-content\plugins\plugin-name\admin\partials\list_ct.php

<?php  
	echo 'gggggggggggg list';
?>