Custom field with ID 609387761255876 is not on given object

[Johnny]

I’m trying to create a simple task with custom fields, but getting the error message above.
API Url:
https://app.asana.com/api/1.0/tasks

Here is my json code :

{
  "data": {
    "workspace": "592101482299309",
    "name": "Section 1 | Design and Planning-417",
    "notes": "",
    "custom_fields": {
      "609387761255876": "Design Labour 3hrs"
    }
  }
}

Please let me know the solution .Thanks

[Bastien_Siebman]

My guess is that your format is incorrect. If you look at the below link and image you can see they are specifying an id field at least.

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