OIDC login (Authelia)

My version of HedgeDoc is: ``

I am trying to set up HedgeDoc to log in via OIDC and my Authelia installation. Following the documentation at OpenID Connect (OIDC) - HedgeDoc 2 Docs I ended up with the following docker compose file environment:

      - TZ=Europe/Paris
      - CMD_DOMAIN=hedgedoc.XXX.YYY
      - CMD_URL_ADDPORT=false
      - CMD_PROTOCOL_USESSL=false
      - CMD_DB_DIALECT=sqlite
      - CMD_DB_STORAGE=./db.sqlite
      - HD_DOMAIN=https://hedgedoc.XXX.YYY # not sure about that one
      # OIDC Configuration
      - HD_AUTH_OIDC_SERVERS=AUTHELIA
      - HD_AUTH_OIDC_AUTHELIA_PROVIDER_NAME=Authelia
      - HD_AUTH_OIDC_AUTHELIA_ISSUER=https://authelia.XXX.YYY
      - HD_AUTH_OIDC_AUTHELIA_CLIENT_ID=hedgedoc
      - HD_AUTH_OIDC_AUTHELIA_CLIENT_SECRET=gk(...)Vq
      - HD_AUTH_OIDC_AUTHELIA_SCOPE=openid profile email groups
      - HD_AUTH_OIDC_AUTHELIA_USER_ID_FIELD=sub
      - HD_AUTH_OIDC_AUTHELIA_USER_NAME_FIELD=preferred_username
      - HD_AUTH_OIDC_AUTHELIA_EMAIL_FIELD=email

This does not even show any “Login with Authelia” button so I guess it is completely off.

I also tried to replace or prepend the HD_ lines with CMD_, no changes.