Changes since SOA version
IXFR is a zone transfer request that returns changes since a specific SOA version. Enter the SOA version to request changes since then.
Not an apex domain
The domain rop33p9c36v8en0atr67h8ug6o04jppt.sk.eserver.net is not the root of its zone.
Instead, try zone transfer on sk.eserver.net .
Instead, try zone transfer on sk.eserver.net .