PATCH /api/v2/conversations/calls/{id} transfer to queue returns 403

Building a sidecar to route calls based on New Relic custom events. Trying to transfer an active call to a specific queue using PATCH /api/v2/conversations/calls/{id}. The service account has conversation:write. Getting a 403 Forbidden.

{
 "to": {
 "id": "queue-uuid",
 "type": "queue"
 }
}

Docs say queue is valid. Is there a specific scope missing or is the endpoint wrong for queue transfers?