How do I see the Session headers from the original request for the web page in Shiny?

In shiny in the server function, how do I see the headers that were in the request that downloaded the web page for the app?
I'm working on windows and looking at the web traffic to the app running in rstudio with fiddler

As per the session documentation https://shiny.rstudio.com/reference/shiny/latest/session.html

request
An environment that implements the Rook specification for HTTP requests. This is the request that was used to initiate the websocket connection (as opposed to the request that downloaded the web page for the app).
Thanks, John.