def METHOD_NAME(self):
    params = {
        "app": "core",
        "module": "global",
        "section": "login",
        "do": "process",
    }
    data = {
        # What's the origin of this key?
        "auth_key": "880ea6a14ea49e853634fbdc5015a024",
        #
        "referer": "https://forum.karagarga.in/",
        "ips_username": self._username,
        "ips_password": self._password,
        "rememberMe": "1",
        "anonymous": "1",
    }
    self._session.post(
        "https://forum.karagarga.in/index.php", params=params, data=data
    )
    if not {"session_id", "pass_hash"}.issubset(self._session.cookies.keys()):
        raise AuthenticationError("Invalid forum username/password")
    logger.debug("Karagarga forum login: OK")