Update app.py

app.py

@@ -205,11 +205,16 @@ if selected_app == "1) Create CSVs":
 if selected_app == "2) Merge CSVs":
     uploaded_files = st.file_uploader("Upload CSV files to merge", accept_multiple_files=True, type="csv")
 
-    if len(uploaded_files) > 1:
-        a = 1
-    else:
-        st.session_state.error = "Please upload at least 2 CSVs to merge"
-        st.session_state.success = None
-        st.session_state.submit = False
-        st.rerun()
+    submit = st.button("Submit")
+    if submit:
+        st.session_state.submit = True
+    
+    if st.session_state.submit:
+        if len(uploaded_files) > 1:
+            a = 1
+        else:
+            st.session_state.error = "Please upload at least 2 CSVs to merge"
+            st.session_state.success = None
+            st.session_state.submit = False
+            st.rerun()