Traefik V2 ACME Error: "Domain name needs at least one dot"

Hi,

I'm trying use the Docker TLS Challenge but keeps giving this error:

level=error msg="Unable to obtain ACME certificate for domains "whoami-traefik-docker": unable to generate a certificate for the domains [whoami-traefik-docker]: acme: error: 400 :: POST :: https://acme-staging-v02.api.letsencrypt.org/acme/new-order :: urn:ietf:params:acme:error:rejectedIdentifier :: Error creating new order :: Cannot issue for "whoami-traefik-docker": Domain name needs at least one dot, url: " routerName=whoami-service@docker rule="Host(whoami-traefik-docker)" providerName=le.acme

unable to generate a certificate for the domains [whoami-traefik-docker]

Where comes the whoami-traefik.docker?
The domain name in the error is not supposed to be the name insert in Host(mydomain.com)?
Independent of domain I insert we keep showing the same error. Any Idea what I'm missing?

My docker-compose.yml:

version: "3.3"

services:

  traefik:
    image: "traefik:v2.2"
    container_name: "traefik"
    command:
      - "--log.level=INFO"
      - "--api.insecure=true" # Dont do in production
      - "--providers.docker=true"
      - "--providers.docker.exposedbydefault=false"
      - "--entrypoints.websecure.address=:443"
      # LetsEncrypt
      - "--certificatesresolvers.le.acme.email=renatopinheiro@motorline.pt"
      - "--certificatesresolvers.le.acme.storage=/letsencrypt/acme.json"
      - "--certificatesresolvers.le.acme.tlschallenge=true"
      # DEBUG CA server - uncomment for testing
      - "--certificatesresolvers.le.acme.caserver=https://acme-staging-v02.api.letsencrypt.org/directory"
    ports:
      - 443:443
      - 8080:8080
    volumes:
      - "/var/run/docker.sock:/var/run/docker.sock:ro"
      - "./letsencrypt:/letsencrypt"

  whoami:
    image: "containous/whoami"
    container_name: "whoami"
    labels:
      - "traefik.enable=true"
      - "traefik.http.routers.whoami-secure.entrypoints=websecure"
      - "traefik.http.routers.whoami-secure.rule=Host(`mydomain.com`)"
      - "traefik.http.routers.whoami-service.tls.certresolver=le"

Best regards,
Renato Pinheiro

Fixed the problem above by removing the wildcard in the DNS and setting it manually. I didn't know that way only by DNS Challenge (https://docs.traefik.io/https/acme/#wildcard-domains).

Best regards,
Renato Pinheiro