TLJH How to set TLS options for traefik


I am a system administrator at an university and manage a jupyter installation here.
Recently I got an email, that the SSL configuration is not secure and that I should update asap.

I tried to use the following traefik config:

       minVersion = "VersionTLS12"
       sniStrict = true
       cipherSuites = [
      curvePreferences = [
            minVersion = "VersionTLS13"

I both tried to place a file “ssl.toml” in “/opt/tljh/config/traefik_config.d” and “/opt/tljh/state/rules”.

It seems, that the file is completely ignored. What am I missing? Incorrect snytax? Wrong directory?

Kind regards,