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 bt-01-02.bitfibra.com.br is not the root of its zone.
Instead, try zone transfer on bitfibra.com.br .
Instead, try zone transfer on bitfibra.com.br .