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 88f63rd3gd8c55iiuaroi91ijr3oh0fq.outlookmail.dk is not the root of its zone.
Instead, try zone transfer on outlookmail.dk .
Instead, try zone transfer on outlookmail.dk .