Fast API for routing to Streamlit App

I have made a few streamlit apps and am running them on a linux server in docker containers. I want to develop a landing page of sorts that authenticates a user and then shows them the apps they have access to.

The basic logic is as follows:
User navigates to myserver
They get proxied by NGINX to a Fast API landing page
In FastAPI if they are logged in they see what streamlit apps they have access to and can navigate to them
Else they are authenticated against a DB and then shown apps they have access to and then navigate to them.

I can’t get the navigation piece to work. Like how do I route a user to a streamlit app without redirecting them entirely to a different page. I have been looking at mounting the streamlit app, requesting it using websockets or embedding it using iframes in html. As of right now I can only get the iframes to work.

Any ideas or links would be a great help! Thanks