I have a contentful + gatsby + netlify site and I want some of the routes displayed on that site to be behind authentication. Part of my confusion is that none of my routes are static. They are built up dynamically at runtime by gatsby from the content in contentful. There is currently no src/router in my package. Would I leverage this: https://github.com/netlify/create-react-app-lambda/tree/reachRouterAndGoTrueDemo
even though I want none of my routes exist until the build is complete? Could I do this and still leverage SSO? Do I need to turn on identity even if I have using SSO?