I've created react and nodejs simple apps but I don't know how you "read" or use the currently logged in users in a browser. I've seen examples on how to read logged in user (os.userInfo()), but this who is logged into the server at the OS level.
I'd like to know and use the logged in credentials in the browser as (in most environments this is an AD login different from the current user because of entitlement requirements)
Also I don't want to create my own credential store in mongodb or something else as our users don't need another authentication system.
Just a simple "Hello You are logged in as Jake Law" Pointers appreciated. No code sample as I don't know where to start