Outbound Campaign API 403: Zendesk Custom Field Mapping Failure

Is it possible to map Zendesk’s custom ticket fields directly to Genesys Cloud Outbound campaign filters?

We are seeing a 403 Forbidden error when trying to push historical Zendesk data into a new Outbound campaign via the API. The payload includes custom attributes that worked fine in Zendesk but seem to violate GC’s schema validation. The error references ‘invalid filter criteria’. Any advice on bridging this gap?

check your payload structure. custom fields need to be wrapped in the external_contact_attributes object, not passed as top-level keys. the 403 is likely a schema validation fail before it even hits the filter logic.