Remove / Hide Layout Widget

I am building an authentication form (Log in + Sign in) using streamlit-authenticator, for that i created a “login menu” using this code :
placeholder = st.empty()
with placeholder.container():
tab = ="Menu", options=["Log in", "Sign in"])
if tab=="Log in" :
name, authentication_status, username = authenticator.login("Login", "main")
if authentication_status == False:
st.error("Username/password is incorrect")
if authentication_status == None:
st.warning("Please enter your username and password")
if authentication_status:
# The App

The heck is that even using the placeholder, i still have the radio displayed after login.
Is there a way to hide/remove “tab” after login?
Thank you !