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 a7k9t4kb14og2nk1slmml44f79n14o7f.itfhosting.dk is not the root of its zone.
Instead, try zone transfer on itfhosting.dk .
Instead, try zone transfer on itfhosting.dk .