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 c8137057758a48e78157cdd5134c7a2a.v1.radwarecloud.net is not the root of its zone.
Instead, try zone transfer on radwarecloud.net .
Instead, try zone transfer on radwarecloud.net .