DNS acme cluster-issuer.yaml - third time is a charm

cluster-issuer.yaml

apiVersion: cert-manager.io/v1
kind: Issuer
metadata:
  name: letsencrypt-staging
  namespace: cert-manager
spec:
  acme:
    email: [email protected]
    server: https://acme-staging-v02.api.letsencrypt.org/directory
    privateKeySecretRef:
      name: letsencrypt-staging
    solvers:
    - http01:
        ingress:
          class: nginx