How to Hide My WP Customize Admin/Frontend Admin Menus

function plt_hide_my_wp_menus() {
	//Hide "My WP".
	remove_menu_page('mywp');
	//Hide "My WP → My WP".
	remove_submenu_page('mywp', 'mywp');
	//Hide "My WP → Admin".
	remove_submenu_page('mywp', 'mywp_admin');
	//Hide "My WP → Frontend".
	remove_submenu_page('mywp', 'mywp_frontend');
	//Hide "My WP → Log in".
	remove_submenu_page('mywp', 'mywp_login');
	//Hide "My WP → Website".
	remove_submenu_page('mywp', 'mywp_site');
	//Hide "My WP → Update".
	remove_submenu_page('mywp', 'mywp_update');
	//Hide "My WP → Debug".
	remove_submenu_page('mywp', 'mywp_debug');
}

add_action('admin_menu', 'plt_hide_my_wp_menus', 10001);

Where do I put this code?