code: def streamlit_ui():
      import streamlit as st
  
      st.header("Admin Configuration")
  
      # Add a navigation sidebar
      st.sidebar.title("Navigation")
      page = st.sidebar.radio(
          "Go to",
          ("Proxy Setup", "Add Models", "List Models", "Create Key"),
      )
  
      # Initialize session state variables if not already present
      if "api_url" not in st.session_state:
          st.session_state["api_url"] = None
      if "proxy_key" not in st.session_state:
          st.session_state["proxy_key"] = None
  
      # Display different pages based on navigation selection
      if page == "Proxy Setup":
          # Use text inputs with intermediary variables
          input_api_url = st.text_input(
              "Proxy Endpoint",
              value=st.session_state.get("api_url", ""),
              placeholder="http://0.0.0.0:8000",
          )
          input_proxy_key = st.text_input(
              "Proxy Key",
              value=st.session_state.get("proxy_key", ""),
              placeholder="sk-...",
          )
          # When the "Save" button is clicked, update the session state
          if st.button("Save"):
              st.session_state["api_url"] = input_api_url
              st.session_state["proxy_key"] = input_proxy_key
              st.success("Configuration saved!")
      elif page == "Add Models":
          add_new_model()
      elif page == "List Models":
          list_models()
      elif page == "Create Key":
          create_key()
  
label_desc: Use image node_id 4 for calling a global function with example usage: streamlit_ui() without return types