Custom Text Plugin Submenu Page

//  Add this plugin to the Admin Navigation Menu ( register the function )
    add_action('admin_menu', 'register_my_plugin_submenu_page');


//  Create a function that contains the admin menu-building code
//  This adds the plugin to the Admin Navigation Menu
    function register_my_plugin_submenu_page() {
    // Create Plugins submenu item
        add_submenu_page(
            'plugins.php',
            'TnT Custom Text Configuration',
            'TnT Custom Text',
            'manage_options',
            'tnt-custom-text',
            'create_the_admin_html_output');
        }