"No default certificate, generating one" when starting Traefik

Hi, I'm using Traefik 2.2.8. I have obtained let's encrypt certificate using cert-manager and stored it in secret, and then I added a TLS Store as follow:

apiVersion: traefik.containo.us/v1alpha1
kind: TLSStore
  name: default
  namespace: traefik

    secretName: le-cert-secret

When starting Traefik, "No default certificate, generating one" is shown in the log, am I missing some configuration?

Thank you.