You may need to create a new folder and add it to a structure.
Folders and generators are items that are managed entirely by Structure add-on, so you'll need to use Structure's services to create the item first, giving you the item identify, and then insert a row into a forest.
Read more about Changing Structure Content for general ideas about updating a structure.
Create the Folder entity
The folder is now stored in the database. Define folder's identity
Add folder to structure
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