Not worth it
The integration doesn't exist. It isn't automatic, other than payment. The data sheet is an advert for a hardware device! The usage instructions are non-existent for the SaaS. Complete garbage. I intentionally bought the least expensive as a method to test before buying all. This is basically a hustle.
That you for trying Fortinet Managed Rules for AWS WAF and providing feedback. Since your trial, Fortinet has posted detailed setup video that may address some of your configuration questions: "Fortinet Managed Rules for AWS WAF Video Tutorial" (link: https://embed.vidyard.com/watch/TEn2L4EqtaEgqfvqmFJ1at), to assist with the initial configuration.