Annotation HTTP API not setting dashboardId and panelId

1

I’m trying to add an annotation to a panel vie the api, but it doesn’t seem to be working. I must be doing something wrong but can’t figure out what:

[nav] In [42]: headers
Out[42]: {'Authorization': 'Bearer eyJrIjoiRUJpNXdNS1pWVDFRR1AyczdjYzVxT1hOTXAyMHM4aGoiLCJuIjoiamFrb2ItYW5ub3RhdGUiLCJpZCI6MX0='}

[ins] In [43]: data = {
          ...:         "dashboardId": 12,
          ...:         "panelId": 2,
          ...:         "time":1583398712873,
          ...:         "timeEnd": 1583398712873,
          ...:         "tags": ["test", "test2"],
          ...:         "text": "something",
          ...:     }
          ...:

[nav] In [44]:         response = requests.post(
          ...:             base_url, headers=headers, data=data
          ...:         ).json()
          ...:

[ins] In [45]: response
Out[45]: {'id': 792, 'message': 'Annotation added'}

This then appears when I query the same api:

{'id': 792,
  'alertId': 0,
  'alertName': '',
  'dashboardId': 0,
  'panelId': 0,
  'userId': 0,
  'newState': '',
  'prevState': '',
  'created': 1583406144169,
  'updated': 1583406144169,
  'time': 1583398712873,
  'timeEnd': 1583398712873,
  'text': 'something',
  'tags': ['test', 'test2'],
  'login': '',
  'email': '',
  'avatarUrl': '',
  'data': {}}]

I must be doing something wrong, but as you can see the dashboardId is not being set and neither is the panelid.
The dashboard and the panel both exist. This is a manually added annotation:

 {'id': 760,
  'alertId': 0,
  'alertName': '',
  'dashboardId': 12,
  'panelId': 2,
  'userId': 0,
...