To get AI answers in your knowledge base, you will have to enable AI for your your knowledge base be following the steps here.
Once you have AI enabled for your source inside KBAnywhere, you can directly get an answer to a question that you type in the search field using information from your knowledge base.
Type your question in the search field and click on the "Ask AI" button.
The "Ask AI" button will be available only if AI has been properly configured for your knowledge base.
