Categories do not appear

[fredarend]

Hello! I own a CPT called Gallery and a CPT Taxonomy called Gallery Category.

In the "Categories (Custom Post Type)" widget, in the "Taxonomy" field the CPT Category Gallery does not appear.

As the image below:

[thingsym]

Hi!

What is the setting of the hierarchical option of the register_taxonomy function?

hierarchical (boolean) (optional) Is this taxonomy hierarchical (have descendants) like categories or not hierarchical like tags. Default: false

Reference: https://codex.wordpress.org/Function_Reference/register_taxonomy

By hierarchical option,

If false, use "Tag Cloud (Custom Post Type)" as tags. If true, use "Categories (Custom Post Type)" as categories.