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 _ffc63b74eae13b0d942d1071954d57a7.demo.ivcert.net is not the root of its zone.
Instead, try zone transfer on sdgjtdhdhz.acm-validations.aws .
Instead, try zone transfer on sdgjtdhdhz.acm-validations.aws .