Passing data to the first login flow

I would like to pass some date from one authenticator provider to another that is inside a first broker login (FBL) flow. I was planning to store the data in a “session note”. However, the session is reset just before entering into the FBL.

Also the idea is that the data is used before the user is created.

I don’t understand the session lifecycle and why it is cleared.

Any advice is appreciated