Can't attach submenu to a top level menu

[shaonsina]

I've created a top level menu for my specific need.
After that I would like to create a submenu and attach it to the top level menu by Carbon Fields and creating the options for the page.
But it noting working.

see the below code:

	function add_menu() {
		add_menu_page(
			esc_html__('Configuration', 'test'),
			esc_html__('TEST', 'test'),
			'manage_options',
			'test-configure',
			'configure_page',
			'dashicons-admin-generic',
			'50'
		);
	}
	add_action( 'admin_menu', 'add_menu' );

	Container::make( 'theme_options', esc_html__( 'Settings', 'test' ) )
		->set_page_menu_title( 'Settings' )
		->set_page_parent( 'test-configure' )
		->set_page_file( 'admin.php?page=test-settings' )
		->add_fields( [
			Field::make ...
		] );

[faustort]

Just a tip, have you tried:
[...]

		->set_page_parent( 'admin.php' )
		->set_page_file( 'test-configure' )

[...]

I've done a test here, and it worked for me.