Flatly does not offer demos. The service is designed to be intuitive and turnkey so usually a 10-15 minute self-guided tour is enough to get up and running.
Flatly's Knowledge Base is quite extensive and provides a number of helpful articles.
Lawnroller or higher plans offer some in-product support. See Pricing
Request an Expert
Additionally, if professional services are required in a long-term engagement, Flatly maintains a network of external third party consultants who are available for paid engagements. See https://flatly.io/request-expert