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 16e21r7qvodh7htfguft25naqh5ua93c.itfhosting.dk is not the root of its zone.
Instead, try zone transfer on itfhosting.dk .
Instead, try zone transfer on itfhosting.dk .