It's the most ideal to train the bot using real data. However, if there's no historical data available to be imported, any kind of information would help.
Your virtual agent is part of the customer support team. So think about the kind of information you use to onboard a new team member, that's what can be used to train your virtual agent.
- Help center, knowledege base, or FAQ
- Internal customer support onboarding manual/glossary/handbook
- Reports or analytics of your help center that gives an insight into what the most frequent queries are
- Real examples of how your customers phrase their queries
- Brand guidelines that specify the tone of voice and/or persona