I have a regular categories widget (or "block" in the new terminology), that creates a
<ul> with my categories.
I want to add a fake category for linkbuilding reasons, an entry to this list that points to an external URL.
How can I do?
I found only the_category_list hook but it doesn't seem to do what I need...
Tried also with the filters
block_categories_all and but they are not called. (wp 6.0)