Any success adding “Categories” to content blocks?

Love the plugin!

Has anyone been able to successfully add a Category taxonomy to the Content Blocks custom post type?

This would help us in the backend to better sort the hundreds of content blocks that we created/

About 8 years ago someone posted this code. It *should* work. But it does not bring up a Category metabox in Content Blocks or add it to the Content Blocks archive page.

function reg_tag() {
  register_taxonomy_for_object_type('category', 'content_block');
}

add_action('init', 'reg_tag');