ACME / Top Level Domain?

Traefik Traefik v2 (latest)
1

Lo all,

I'm trying to add a cert for my "bare domain" via LetsEncypt.
I'll add that all my ACME config for my subdomains is working nicely, but the "top level domain" is failing.

I see the following error in my log:

level=error msg="Unable to obtain ACME certificate for domains \"myTLD.co.uk,*.myTLD.co.uk\" : unable to generate a certificate for the domains [myTLD.co.uk]: error: one or more domains had a problem:\n[*.myTLD.co.uk] [*.myTLD.co.uk] acme: error presenting token: mythicbeasts: login: error parsing error: invalid character '<' looking for beginning of value\n[myTLD.co.uk] [myTLD.co.uk] acme: error presenting token: mythicbeasts: login: error parsing error: invalid character '<' looking for beginning of value\n" providerName=mythicbeasts.acme

The TOML for this host is:

  [http.routers.nohost]
    # Define the hostname to be used
    rule = [ "Host(`myTLD.co.uk`)" ]
    # Define the entrypoint
    entrypoints = [ "websecure" ]
    # Target the "nohost" service
    service = "nohost"
    # Define the middlewares to use
    middlewares = [ "blockexternal" ]
    # Enable TLS
    [http.routers.nohost.tls]
      # Specify which resolver to use
      certResolver = "mythicbeasts"
      # Define the domain to use, as it's one higher than the others
      [[http.routers.nohost.tls.domains]]
        main = "myTLD.co.uk"
        sans = [ "*.myTLD.co.uk" ]

My DNS provider API key has worked with everything else - so is this something I'm doing wrong in Traefik config, or is the DNS provider throwing a fit?
(from their docs, my API key "will allow editing of records for any hostname within the zone, including the bare domain name)