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 54.ip-151-80-61.eu is not the root of its zone.
Instead, try zone transfer on ip-151-80-61.eu .
Instead, try zone transfer on ip-151-80-61.eu .