Not an apex domain
The domain _296f140bc4f5d94a00539bdd1544adb3.zbkrxsrfvj.acm-validations.aws is not the root of its zone.
Instead, try zone transfer on zbkrxsrfvj.acm-validations.aws .
Instead, try zone transfer on zbkrxsrfvj.acm-validations.aws .