Personal Connection API outbound call returning 400 Bad Request

Trying to trigger an outbound call via the Personal Connection API instead of using the standard dialer. The docs say I need to POST to /api/v2/omnichannel/interactions with a specific interaction type. I’ve got the OAuth token and the queue ID sorted. The request body looks right based on the swagger spec, but I’m hitting a 400.

{
 "interactionType": "outbound",
 "to": [{
 "address": "+491701234567",
 "type": "phone"
 }],
 "from": {
 "address": "+493012345678",
 "type": "phone"
 },
 "": {
 "queueId": "my-queue-id"
 }
}

The error message is just Invalid request body. I’ve checked the phone number formats and the queue exists. Am I missing a required field in the object? Or is this endpoint restricted to internal test users only? I’ve tried adding a mediaType field but that just breaks it further. What am I missing here?