Architect API 403 when creating Zendesk-style routing rules

Why does the Platform API returns a 403 Forbidden when trying to create routing rules via the Architect API? We are mapping Zendesk trigger conditions to Genesys Cloud routing rules using the SDK v2.1.

  • Verified the integration user has ‘Architect’ and ‘Routing’ scopes enabled.
  • Tested the same payload via Postman with a personal admin token, which succeeded.

The error persists only when using the service account token during our automated migration script. Any ideas on the scope mismatch?