How does the AI know what to say?

From two places, both written by your team.

Your published help articles. Write articles in Knowledge Base (for example: pricing, opening hours, refunds, how to get started) and publish them. Drafts are never used.

Answers your team has already given. When someone on your team answers a customer and marks the conversation resolved or closed, the AI keeps a short, general version of that answer, with names, email addresses and order numbers taken out. It is told to skip answers that were only about one customer's own order or account. You can see every learned answer under Knowledge Base, in "Learned from your team", with a link to the conversation it came from, and Forget any of them.

For each question the AI looks up the closest articles and past answers. If they do not cover the question, it tells the customer a person will follow up instead of guessing. That is how it gets better over time: a question your team answers once is one the AI can answer the next time.