How to find out all required parameters in realtime api

API
1

I am trying to let chat AI start welcome greeting before user prompt and question. Below is my code, it doesn’t work because error. How do I find out required parameters in below example code? I only find realtime conversation response type in below link.
Realtime conversations - OpenAI API

:cross_mark: OpenAI error received: {
“type”: “invalid_request_error”,
“code”: “invalid_value”, …

                    if response['type'] == 'session.created':
                        session_id = response['session']['id']
                        print(f"Session created with ID: {session_id}")
                        open_greeting =  {
                            "type": "response.create",
                            "response": {
                                "conversation": "auto",
                                "modalities": ["audio"],
                                "instructions": "say welcome message",
                            },
                        }
                        await openai_ws.send(json.dumps(open_greeting))