--- a/wp/wp-includes/widgets/class-wp-widget-categories.php	Tue Dec 15 15:52:01 2020 +0100
+++ b/wp/wp-includes/widgets/class-wp-widget-categories.php	Wed Sep 21 18:19:35 2022 +0200
@@ -26,6 +26,7 @@
 			'classname'                   => 'widget_categories',
 			'description'                 => __( 'A list or dropdown of categories.' ),
 			'customize_selective_refresh' => true,
+			'show_instance_in_rest'       => true,
 		);
 		parent::__construct( 'categories', __( 'Categories' ), $widget_ops );
 	}