Update pages/HOW_TO_USE.py

pages/HOW_TO_USE.py

@@ -2,6 +2,10 @@
 import streamlit as st
 import pandas as pd
 
+# at the top of pages/HOW_TO_USE.py, pages/TIME_CYCLE.py, pages/VIBRATION.py, etc.
+from auth import require_login
+require_login(auth_page_name="AUTH", redirect_page="HOW TO USE")
+
 st.set_page_config(page_title="How to use — Gann Vibration", layout="wide")
 
 st.title("📘 How to use — Gann Vibration (Angle) Calculator")