Letsencrypt challange normal and staging possible in parallel?

Traefik Traefik v2 (latest)
1

Continuing the discussion from Untrusted Letsencrypt certificate:
I thought it would be a good idea to try out new domains in staging first and if it works switch to normal.

certificatesResolvers:
  letsEncrypt:
    acme:
      email: "letsencrypt@admindomain.com" # Email address used for registration
      storage: "/etc/traefik/acme/acme.json" # File or key used for certificates storage

      tlsChallenge: {}

  # stage server for testing
  letsEncryptStage:
    acme:
      email: "letsencrypt@admindomain.com" # Email address used for registration
      storage: "/etc/traefik/acme/acme-stage.json" # File or key used for certificates storage
      caServer: "https://acme-staging-v02.api.letsencrypt.org/directory"

      tlsChallenge: {}

But this can't work, because traefik can't make a difference between the requests from Letsencrypt.

How to manage this?