Tips on Customizing Widget Options – Advanced Conditional Visibility for Gutenberg Blocks & Classic Widgets

How to Hide Widget Options Admin Menus

function plt_hide_widget_options_menus() {
	//Hide the "Settings → Widget Options" menu.
	remove_submenu_page('options-general.php', 'widgetopts_plugin_settings');
	//Hide the "Settings → Widget Options Snippets" menu.
	remove_submenu_page('options-general.php', 'edit.php?post_type=widgetopts_snippet');
}

add_action('admin_menu', 'plt_hide_widget_options_menus', 12);

Where do I put this code?

How to Hide Widget Options Meta Boxes

function plt_hide_widget_options_metaboxes() {
	$screen = get_current_screen();
	if ( !$screen ) {
		return;
	}

	//Hide the "Snippet Code" meta box.
	remove_meta_box('widgetopts_snippet_code', $screen->id, 'normal');
	//Hide the "Description" meta box.
	remove_meta_box('widgetopts_snippet_description', $screen->id, 'normal');
	//Hide the "Help & Examples" meta box.
	remove_meta_box('widgetopts_snippet_help', $screen->id, 'side');
}

add_action('add_meta_boxes', 'plt_hide_widget_options_metaboxes', 20);