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 yjgct5wthn9n.fips.yxbq.mail-manager-smtp.amazonaws.com. is not the root of its zone.
Instead, try zone transfer on fips.yxbq.mail-manager-smtp.amazonaws.com .
Instead, try zone transfer on fips.yxbq.mail-manager-smtp.amazonaws.com .