Update app.py

app.py

@@ -64,7 +64,9 @@ def send_text(token, text):
     })
 
 def get_username(payload):
-    url = f"https://api.line.me/v2/bot/group/{payload.get("group_id")}/member/{payload.get("user_id")}"
+    group_id = payload.get("group_id")
+    user_id = payload.get("user_id")
+    url = f"https://api.line.me/v2/bot/group/{group_id}/member/{user_id}"
     try:
         res_json = requests.get(url, headers={"Authorization": "Bearer " + LINE_CHANNEL_ACCESS_TOKEN}).json()
         return res_json.get("displayName")