>what if a customer wants a drink it doesn't carry?

I will be very polite here and assume there's genuine good faith with this idea. Undeservedly so.

It should take a note of failed orders, aggregate statistics for what requests it received, and a human reviewer should use that to determine what inventory to shop for for next time. That would he valuable.

Anyone who worked a day in customer service, or even IT, can tell you you need to sanitize your inputs. And LLMs are very bad at saying "this is a useless request " Learning a new popular drink is great. People wanting PS5's from a vending machine is a useless request.