Error: Request failed with status code 400string(262) "{
  "error": {
    "message": "You must provide the 'OpenAI-Beta' header to access the Assistants API. Please try again by setting the header 'OpenAI-Beta: assistants=v2'.",
    "type": "invalid_request_error",
    "param": null,
    "code": "invalid_beta"
  }
}"