WP Categories Metabox Extended extends the Category metabox on your WordPress editor. Once installed the Category metabox gets a search bar with which you search Categories. Also, this is only seen on “Add New Post” screen in the WordPress Admin dashboard.
From WordPress 5.0, the search bar is included with the Categories metabox. In case you choose to use the Classic editor by using plugins like Disable Gutenberg, then WP Categories Metabox Extended plugin will continue to extend the Categories metabox for the default “Post” post type.
