error: error validating “john.yaml”: error validating data: ValidationError(CertificateSigningRequest.spec): missing required field “signerName” in io.k8s.api.certificates.v1.CertificateSigningRequestSpec; if you choose to ignore these errors, turn validation off with --validate=false
Thanks for sharing the link @karkarbhautik.
I just checked the mock exam, and the problem is that the video was made with an earlier version of Kubernetes.
But you can check a message about this in the question itself and also a note mentioning this change from 1.19 (and you can also see that the solution is correct using the signerName parameter):