Update app.py

app.py

@@ -103,7 +103,11 @@ st.markdown("#### Have a conversaion with 1984 by George Orwell 🙊")
 
 with st.sidebar:
     api_key = st.text_input(label = "Paste your OpenAI API key here to get started", type = "password")
-    os.environ["OPENAI_API_KEY"] = api_key
+
+    if api_key:
+        os.environ["OPENAI_API_KEY"] = api_key
+    else:
+        os.environ["OPENAI_API_KEY"] = None
 
     st.info("This isn't saved 🙈")