Where is my newly created Taxonomy or Post Type in the Block Editor (Gutenberg)?

Enabling REST API can allow your Custom Post Types & Taxonomies to be visible to the Block Editor.

By default, the REST API configuration is not enabled on newly created Custom Taxonomies or Custom Post Types. If you’re adding a Custom Taxonomy to a post type that is by default using the Block Editor (Pages or Posts), you need to go under the REST API tab and select the option to ‘Enable REST API

Enable REST API in Pods


You do not need to edit any of the other fields in this setting, as the remainder are specific to the REST API settings.

Enabling REST API will make the Custom Post Type available to the Block Editor and will allow your Custom Taxonomies to also show up in the Block Editor.