default path to $ in redis fixed the issue

db.py

@@ -60,7 +60,6 @@ def add_chat_by_uid(client: Redis, chat: Chat, uid: str):
 
 
 if __name__ == "__main__":
-
     client = get_client()
     user = User(username="foo", uid="afa03747-a9ce-4200-964c-7816ec381fa9")
     chat = Chat(patient="foo", messages=[("a", "b"), ("c", "d")])