Update app.py

app.py

@@ -5,7 +5,7 @@ import requests
 api_url = "https://airline-agent.vercel.app/chat"
 print("start response------------------------------------------------------")
 
-def respond(message: str, history: List[Dict[str, str]]) -> Tuple[str, List[Dict[str, str]]]:
+def respond(message: str, history: List[Dict[str, str]]) -> tuple[str, List[Dict[str, str]]]:
     try:
         response = requests.post(api_url, json={"message": message})
         if response.status_code == 200: