To change the name or description of a data source, select the pencil icon below the data source name:
In the Update data source modal, enter the new name or description and choose Update.
Select the Indexing Configuration option. In the pop-out menu that appears, enter the new setting and choose Update Indexing Configurations.
The definition of this setting and how to use it is provided in the article Adding Documents to a Knowledge Base.
The changes will apply to new content that is added and indexed or to existing content that is reindexed.