POST /api/v2/conversations/calls returns 400 with 'invalid argument'

NICE CXone API & Integrations
1

Trying to kick off an outbound call via the JS SDK but hitting a wall. The endpoint POST /api/v2/conversations/calls keeps spitting back a 400 even though the JSON looks valid. Here’s the payload I’m sending.

{
 "to": [{ "phoneNumber": "+1234567890" }],
 "from": { "phoneNumber": "+0987654321" },
 "type": "phone"
}

Docs say it needs a routingData object but the schema isn’t clear on the required fields. What am I missing?