POST /api/v2/conversations/calls 400 Bad Request on agent-initiated outbound

Trying to trigger an outbound call for an agent via the API but getting a 400. The payload looks right based on the docs.

POST /api/v2/conversations/calls
{
 "to": [{"phoneNumber": "+15550199", "name": "Test"}],
 "from": {"phoneNumber": "+15550100"},
 "Data": {"queueId": "q-123"},
 "type": "outbound",
 "provider": {"id": "prov-xyz"},
 "wrapUpCode": {"id": "wu-1"}
}

Response is just "message":"Invalid request". No details on what’s broken. Is Data supposed to be there for this endpoint?