QUESTION: Port Example to FastAPI Framework?

Has anyone ported this exact example to FastAPI as an MVC app (as opposed to just API)? Seems like a super simple example and it works great in Flask but it's giving me fits in FastAPI. I can get it to log in but having issues accepting the token at the call back URI. Does anyone have an example of this in FastAPI, or willing to put a quick example together? I'd be grateful.