import requests


def set_website_preference_for_header(
    url_pref: str,
    session: requests.Session,
) -> requests.Session:
    """
    Set the 'Email Headers' of the 'Archive Preferences' for the auth session
    to 'Show All Headers'. Otherwise only a restricted list of header fields is
    shown.
    """
    url_archpref = url_pref + "&TAB=2"
    payload = {
        "Email Headers": "b",
    }
    session.post(url_archpref, data=payload)
    return session