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 _664F5E4F69DDABCCE9F2F23B5FD1E583.solver.net.ua is not the root of its zone.
Instead, try zone transfer on solver.net.ua .
Instead, try zone transfer on solver.net.ua .