The first thing you'll need to configure after you've installed cert-manager is an issuer which you can then use to issue certificates.
This section documents how the different issuer types can be configured. You might want to
read more about
ClusterIssuer resources here.
cert-manager comes with a number of built-in certificate issuers which are denoted by being in
cert-manager.io group. You can also install external issuers in addition to the built-in types.
Both built-in and external issuers are treated the same and are configured similarly.
ClusterIssuer resource types, ensure you understand the purpose of the
Cluster Resource Namespace; this can be a common source
of issues for people getting started with cert-manager.