How is allocationByFormat set in createOrReplaceInventoryItem?

[oc_breaks]

Does anyone happen to know how 'allocationByFormat' is determined when creating an item? It's not able to be set in the request to create an inventory item and when specifying 'shipToLocationAvailability.quantity' they are automatically all allocated to 'fixedPrice'. How does one go about specifying that these should be available for auction instead?

My request to createOrReplaceInventoryItem is:

{
  "condition": "USED_VERY_GOOD",
  "conditionDescriptors": [
    {
      "name": "40001",
      "values": [
        "400010"
      ]
    }
  ],
  "availability": {
    "shipToLocationAvailability": {
      "quantity": 1
    }
  },
  "product": {
    "title": "2022 Panini Court Kings Chet Holmgren Oklahoma City Thunder Dressed To Impress",
    "description": "test description",
    "aspects": {
      "Sport": [
        "Basketball"
      ]
    },
    "imageUrls": [
      {removed for this post}
    ]
  }
}

And when calling getInventoryItem:

{
    "sku": "test-sku-1",
    "locale": "en_US",
    "product": {
        "title": "2022 Panini Court Kings Chet Holmgren Oklahoma City Thunder Dressed To Impress",
        "aspects": {
            "Sport": [
                "Basketball"
            ]
        },
        "description": "test description",
        "imageUrls": [
            {removed for this post}
        ]
    },
    "condition": "USED_VERY_GOOD",
    "availability": {
        "shipToLocationAvailability": {
            "quantity": 1,
            "allocationByFormat": {
                "auction": 0,
                "fixedPrice": 1
            }
        }
    },
    "conditionDescriptors": [
        {
            "name": "40001",
            "values": [
                "400010"
            ]
        }
    ]
}

I'm having a lot of trouble publishing this as an auction offer and I'm wondering if this is why