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 sg6sa03phrlsn2j4pl4gj73en3q1d0uv.itfhosting.dk is not the root of its zone.
Instead, try zone transfer on itfhosting.dk .
Instead, try zone transfer on itfhosting.dk .