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 b547qgquk6bic0afln5f3lgt28r02dvm.dnsfactory.dk is not the root of its zone.
Instead, try zone transfer on dnsfactory.dk .
Instead, try zone transfer on dnsfactory.dk .