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 i0ftpf5lv8f6cd9snhgbvplc010b8im6.outlookmail.dk is not the root of its zone.
Instead, try zone transfer on outlookmail.dk .
Instead, try zone transfer on outlookmail.dk .