Same here. I know it hurts to offer a free trial for something that already costs you money to serve (those API calls won't be free), but it's really hard to sign up without trying it first.
what's to say you won't add specific optimizations by hand now that aren't included in the product out of the box?
edit: ah, just saw your other comment about being afraid free trial gets out of hand financially
a solution could be to only allow x number of free tokens for a given demo chatbot