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 b39i8lkk9qtbr3ttlkcfv56p22u3ovdd.boerneloppen.dk is not the root of its zone.
Instead, try zone transfer on boerneloppen.dk .
Instead, try zone transfer on boerneloppen.dk .