microk8s enable helm3 ingress
microk8s kubectl create namespace cert-manager
microk8s helm3 repo add jetstack https://charts.jetstack.io
microk8s helm3 repo update

microk8s helm3 install cert-manager jetstack/cert-manager \
  --namespace cert-manager \
  --set installCRDs=true \
  --set ingressShim.defaultIssuerName=letsencrypt-production \
  --set ingressShim.defaultIssuerKind=ClusterIssuer \
  --set ingressShim.defaultIssuerGroup=cert-manager.io

microk8s kubectl apply -f - <<YAML
apiVersion: cert-manager.io/v1alpha2
kind: ClusterIssuer
metadata:
  name: letsencrypt-production
spec:
  acme:
    email: CHANGEME@example.com
    server: https://acme-v02.api.letsencrypt.org/directory
    privateKeySecretRef:
      name: letsencrypt-production-issuer-account-key
    solvers:
    - selector: {}
      http01:
        ingress:
          class: nginx
YAML