Update src/app.py

src/app.py

@@ -10,6 +10,7 @@ with demo:
     submit_button.click(pdf_chatbot.add_text, inputs=[chat_history, txt], outputs=[chat_history], queue=False).\
         success(pdf_chatbot.generate_response, inputs=[chat_history, txt, uploaded_pdf,slider_chunk_size,slider_overlap_percentage,slider_temp,slider_k], outputs=[chat_history,txt]).\
         success(pdf_chatbot.render_file, inputs=[uploaded_pdf], outputs=[show_img])
+    download_button.click(fn=chat_history, inputs=[], outputs=output)
 
 if __name__ == "__main__":
     demo.launch()