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 _32caf0586ef902bc2a0c1f4968d10887.spf.dnssmarthost.net is not the root of its zone.
Instead, try zone transfer on spf.dnssmarthost.net .
Instead, try zone transfer on spf.dnssmarthost.net .