Architect Script API 400 Error on Legal Hold Export

Having some config trouble here for the script export endpoint. Getting a 400 Bad Request when trying to pull transcript metadata for a discovery case in London.

{
 "view": "FULL",
 "groupBy": [
 "conversationId"
 ],
 "query": "type:webchat AND scriptId:abc-123"
}

The endpoint is POST /api/v2/analytics/conversations/export. Any ideas?