senderpro-mta-3.base.signa.run IXFR zone transfer

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 senderpro-mta-3.base.signa.run is not the root of its zone.
Instead, try zone transfer on base.signa.run .