plugin-controls/plugin_controls.php

<?php

/*
Plugin Name: Plugin Control
Plugin URI: https://cooini.com/services/dev/wordpress
Description: This plugin will disable access to the plugins and other pages
Version: 1.0
Author: sbyrd
Author URI: https://cooini.com/
License: MINE-all-mine
*/

function plugin_controls_remove_menus()
{
    $allow_plugin_file = plugin_dir_path(__FILE__)."/.allow_plugin_list";

    if (isset($_GET['allow_plugin_list']) and $_GET['allow_plugin_list'] === "123letmesee")
    {
        touch( $allow_plugin_file );
    }
    //

    if (!file_exists($allow_plugin_file)) {
        remove_menu_page('plugins.php');
        remove_menu_page('update-core.php');
    }

}
function plugin_page_control()
{
    $allow_plugin_file = plugin_dir_path(__FILE__)."/.allow_updates";

    if (isset($_GET['allow_updates']) and $_GET['allow_updates'] === "123letmeupdate")
    {
        touch( $allow_plugin_file );
    }
    else
    {
        if (file_exists($allow_plugin_file) and (time() - filectime($allow_plugin_file) >= 60 * 60 * 12  ))
        {
            // File is older than threshold, delete
            unlink($allow_plugin_file);
        }
    }

    //

    if (file_exists($allow_plugin_file))
    {
        define( 'DISALLOW_FILE_EDIT', false ); // allow
        define( 'DISALLOW_FILE_MODS', false);
    }
    else
    {
        define( 'DISALLOW_FILE_EDIT', true ); // disable
        define( 'DISALLOW_FILE_MODS', true);
    }
}

add_action( 'admin_menu', 'plugin_controls_remove_menus' );
add_action( 'admin_menu', 'plugin_page_control' );