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 6n3kbiq3nrg476emk1gqtocgpqm2bq1b.comtecint.dk is not the root of its zone.
Instead, try zone transfer on comtecint.dk .
Instead, try zone transfer on comtecint.dk .