Errors

invalid_contact_ids

Those are not contact ids

contact_ids is a list of ids from GET /v1/contacts, not phone numbers.

What to do

Send the id of each contact. If you have numbers rather than ids, add them as contacts first with POST /v1/contacts, which returns the id.

The shape

{
  "error": {
    "type": "...",
    "code": "invalid_contact_ids",
    "message": "...",
    "docs": "https://docs.njiwa.upeo.ai/errors/invalid_contact_ids"
  }
}