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 _197c546f73f9df327d096dfad820cf7f.mhbtsbpdnt.acm-validations.aws is not the root of its zone.
Instead, try zone transfer on mhbtsbpdnt.acm-validations.aws .
Instead, try zone transfer on mhbtsbpdnt.acm-validations.aws .