That is an error
You were directed here because a TPP made an invalid request.
If you are using sandbox, re-start your sequence and try again.
Technical Error Message:
[
  {
    "cmsKey": "creationError",
    "params": {
      "error": "invalid_grant",
      "error_description": "mandatory_query_parameter_missing: one or more query parameters missing. Got  Required client_id",
      "redirect": false
    }
  }
]