cluster-issuer dns

crie o secret

apiVersion: v1
kind: Secret
metadata:
  name: cloudflare-api-key
type: Opaque
stringData:
  api-key: seu-token-aqui

crie o cluster issuer

apiVersion: cert-manager.io/v1
kind: ClusterIssuer
metadata:
  name: letsencrypt-cloudflare-prod
spec:
  acme:
    server: https://acme-v02.api.letsencrypt.org/directory
    email: email@usado.na.cloudflare
    privateKeySecretRef:
      name: letsencrypt-cloudflare-prod
    solvers:
    - dns01:
        cloudflare:
          email: email@usado.na.cloudflare
          apiKeySecretRef:
            name: cloudflare-api-key
            key: api-key

o e-mail tem que ser o mesmo da conta que criou o token.