updated secret name

app.py

@@ -41,11 +41,11 @@ if use_custom_credentials:
 
         submit_button = st.form_submit_button("Connect")
 else:
-    hivemq_host = os.getenv("HIVEMQ_HOST")
-    hivemq_username = os.getenv("HIVEMQ_USERNAME")
-    hivemq_password = os.getenv("HIVEMQ_PASSWORD")
-    hivemq_port = os.getenv("HIVEMQ_PORT")
-    reactor = os.getenv("REACTOR")
+    hivemq_host = os.getenv("host")
+    hivemq_username = os.getenv("username")
+    hivemq_password = os.getenv("password")
+    hivemq_port = os.getenv("port")
+    reactor = os.getenv("reactor")
 
     # button to submit the form
     if st.session_state["experiment"] is None: