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 1r1d18p2hq3kgeo5fubqghd6bleuhoqu.mailcloud.dk is not the root of its zone.
Instead, try zone transfer on mailcloud.dk .
Instead, try zone transfer on mailcloud.dk .