add specific file name

main.py

@@ -1,4 +1,5 @@
 import re
+import datetime
 import streamlit as st
 
 from transformers import pipeline
@@ -15,7 +16,7 @@ st.markdown("""
 """)
 st.subheader("Translation made fast and easy.")
 
-with st.expander("❓ How does it work"):
+with st.expander(label="❓ How does it work", expanded=True):
     st.markdown("""
     **Translator** is a **simple tool** that allows you to **translate text** from one language to another.
 
@@ -84,4 +85,9 @@ else:
 
         st.success("🗣️ Translated!")
         st.write(f"**Translation:** {' '.join(text_to_translate)}")
-        st.download_button("Download translated text", "\n".join(text_to_translate), "text/plain")
+        st.download_button(
+            label="Download translated text", 
+            data="\n".join(text_to_translate), 
+            file_name=f"{st.session_state['input_lang']}-{st.session_state['output_lang']}-{datetime.now().strftime('%Y-%m-%d-%H-%M-%S')}.txt",
+            mime="text/plain"
+        )