I did it by this: "voice": { "provider": "cartesia", "voiceId": "5345cf08-6f37-424d-a5d9-8ae1101b9377", "model": "sonic-english" }, but still showing : Assistant configuration is invalid on the Publish button ( All this is happening directly on my Vapi dashboard: https://dashboard.vapi.ai/assistants/b461a.....) I need to create the assitant via api but then still working on the configurations on the Vapi side. Can you someone help to explain?