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 us20-0d41a32a-53cf1302065acd65dbf0823c9.pages.mailchi.mp.isghn.net is not the root of its zone.
Instead, try zone transfer on isghn.net .
Instead, try zone transfer on isghn.net .