Reference to the issuer responsible for issuing the certificate.
If the issuer is namespace-scoped, it must be in the same namespace
as the Certificate. If the issuer is cluster-scoped, it can be used
from any namespace.
The `name` field of the reference must always be specified.
group
string
Group of the issuer being referred to.
Defaults to 'cert-manager.io'.
kind
string
Kind of the issuer being referred to.
Defaults to 'Issuer'.
name
string required
Name of the issuer being referred to.