Letsencrypt comment utiliser --préféré-défis

Cette commande:

$ letsencrypt certonly --manual --preferred-challenges dns --email [email protected] --domains test001.bar.com

sorties:

letsencrypt: error: unrecognized arguments: --preferred-challenges dns

À partir de la documentation ici: https://certbot.eff.org/docs/using.html#certbot-command-line-options

J'ai trouver:

  --preferred-challenges PREF_CHALLS
                        A sorted, comma delimited list of the preferred
                        challenge to use during authorization with the most
                        preferred challenge listed first (Eg, "dns" or "tls-
                        sni-01,http,dns"). Not all plugins support all
                        challenges. See
                        https://certbot.eff.org/docs/using.html#plugins for
                        details. ACME Challenges are versioned, but if you
                        pick "http" rather than "http-01", Certbot will select
                        the latest version automatically. (default: [])

Pourquoi j'ai cette erreur?