curl --request PATCH \
  --url https://api.attio.com/v2/tasks/{task_id} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
  "data": {
    "deadline_at": "2023-01-01T15:00:00.000000000Z",
    "is_completed": false,
    "linked_records": [
      {
        "target_object": "people",
        "target_record_id": "891dcbfc-9141-415d-9b2a-2238a6cc012d"
      }
    ],
    "assignees": [
      {
        "referenced_actor_type": "workspace-member",
        "referenced_actor_id": "50cf242c-7fa3-4cad-87d0-75b1af71c57b"
      }
    ]
  }
}'

{
  "data": {
    "id": {
      "workspace_id": "14beef7a-99f7-4534-a87e-70b564330a4c",
      "task_id": "649e34f4-c39a-4f4d-99ef-48a36bef8f04"
    },
    "content_plaintext": "Follow up on current software solutions",
    "deadline_at": "2023-01-01",
    "is_completed": false,
    "linked_records": [
      {
        "target_object_id": "people",
        "target_record_id": "891dcbfc-9141-415d-9b2a-2238a6cc012d"
      }
    ],
    "assignees": [
      {
        "referenced_actor_type": "workspace-member",
        "referenced_actor_id": "50cf242c-7fa3-4cad-87d0-75b1af71c57b"
      }
    ],
    "created_by_actor": {
      "type": "workspace-member",
      "id": "50cf242c-7fa3-4cad-87d0-75b1af71c57b"
    },
    "created_at": "2022-11-21T13:22:49.061281000Z"
  }
}