Adding Custom Fields to WO Error

Hi,

Would anyone be able to help me work out where I have gone wrong with this please?

Error: {"ErrorMessage":"Descriptor is a required field.","ErrorCode":"ERROR_CODE_1","TimeStamp":"2025-02-11T15:50:51.7472408Z"}

Code I am trying to push through the API:

{
"Entity": {
"Id": 110710,
"CustomFields": [
{
"Descriptor": {
"ActorTypeId": "WO",
"Id": 1102
},
"ObjectTypeId": "WO",
"Value": "Yes"
},
{
"Descriptor": {
"ActorTypeId": "WO",
"Id": 1106
},
"ObjectTypeId": "WO",
"Value": "1"
}
]
},
"Properties": [
"Id",
"CustomFields.Id",
"CustomFields.Value"
],
"ConcurrencyId": 1
}

Thanks.