Here's information about the assetType property, and here is a list of the asset types. There hasn't been documentation released yet regarding filtering for these routes, but this should work in the payload:

{
    "query": {
        "property": "assetType.id",
        "simpleOperator": "equals",
        "valueType": "int",
        "value": 209
    }
}

Here's information about the assetType property, and here is a list of the asset types. There hasn't been documentation released yet regarding filtering for these routes, but this should work in the payload:

{
    "query": {
        "property": "assetType.id",
        "simpleOperator": "equals",
        "valueType": "int",
        "value": 207
    }
}