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 v15u41hvv2netl76d53kdg00r5dj6u42.dnsfactory.dk is not the root of its zone.
Instead, try zone transfer on dnsfactory.dk .
Instead, try zone transfer on dnsfactory.dk .