c688bfca6cba2e723ebc72cb60f94bcd.f306ef661c48ed4edb0fa185813a5793.643671857.sectigo.com 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 c688bfca6cba2e723ebc72cb60f94bcd.f306ef661c48ed4edb0fa185813a5793.643671857.sectigo.com is not the root of its zone.
Instead, try zone transfer on sectigo.com .