What response format will I get from rasa train callback_url?

hello, I am using rasa train API where I’m passing callback_url in query parameter and I want to parse the response In the same callback_url how can I get the response? on the rasa server, it is showing below error:

raise ClientResponseError(

aiohttp.client_exceptions.ClientResponseError: 422, message=‘Unprocessable Entity’, url=URL(‘https://c70c-43-248-34-168.ngrok-free.app/chatbot/update_train_status’)

and below is my callback_url endpoint:

@router_update.post(“/chatbot/update_train_status”) async def chatbot_update_train_status(request: Request, filename: str = Header(default=None), req_data: ChatbotTrainUpdateStatusRequest = Depends( ChatbotTrainUpdateStatusRequest.as_form)): print(req_data.TrainingResult) print(filename) return

also what is the response format that rasa will send in callback_url once model is trained?