There are many using FusionAuth in this manner, we don't currently offer any specific documentation on integrating with API Gateways.

I would love to have this documentation at some point, however as far as I know most if not all of the options I've seen have a fairly standard integration using a JWT.

Once you know what the Gateway such as Kong is looking for in the JWT to perform authorization you can use the JWT populate lambda to ensure the JWT has everything you need.

https://fusionauth.io/docs/v1/tech/lambdas/jwt-populate
https://fusionauth.io/docs/v1/tech/oauth/tokens

Hope that helps!