Update app.py

app.py

@@ -35,7 +35,7 @@ if submit_button and st.session_state['usr_text']:
     response = llm_gemini.invoke(st.session_state['usr_text'])
     st.subheader("Answer:")
     st.write(response.content)    
-    st.session_state.chat_history.append(f'User: {st.session_state['usr_text']} \nAI: {response.content}')
+    st.session_state.chat_history.append(f'User: {st.session_state["usr_text"]} \nAI: {response.content}')
 
 # for displaying chat history
 chat_history_text = "\n\n".join(st.session_state.chat_history)