Currently, Iglu Central doesn’t support the schema list endpoints that is supported by a Iglu Server. It will start to support it after 1st November 2021. Until that date, you need to use your private Iglu server with RDB Loader. Can you confirm you copied Iglu Central schemas to your private Iglu server ? If you didn’t do that yet, you can follow this documentation. Let me know if this solves your problem.