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 16lm3t0li9na67f3q92ctfh3jjg019aa.resennet.dk is not the root of its zone.
Instead, try zone transfer on resennet.dk .
Instead, try zone transfer on resennet.dk .