Start by creating a new Ingestion under Search > Configure Search > Classic Ingestion > Internal Knowledge
Setup Knowledge Bases
Wizard Mode
Advanced Mode
In the Advanced mode, in order to ingest articles from a category or folder, users are required to define the Start URL. The two common formats are:

Please note that configuring individual folders with the /solutions/folders endpoint will not work. I.e. the following format is explicitly unsupported for folder configuration:
solutions/articles?folder_id= as shown above.