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 6211a6821f3af63cd7a92aac6d0a5396.f7a50e10685bf25583f8e6fb6ca6988b.64898ecb37c68.sectigo.com is not the root of its zone.
Instead, try zone transfer on sectigo.com .
Instead, try zone transfer on sectigo.com .