Not redirected to SSL/acme.json empty - docker

Question

I am using traefik as reverse proxy for cryptpad. Traefik is running in a docker container. I used this docs to solve this issue: https://github.com/xwiki-labs/cryptpad/wiki/Docker-(with-Nginx-and-Traefik)#configuring-traefik
That's what I did:
$ mkdir traefik && cd traefik
$ wget https://raw.githubusercontent.com/containous/traefik/master/traefik.sample.toml
$ mv traefik.sample.toml traefik.toml
$ touch acme.json && chmod 600 acme.json
I added this to traefik.toml:
[entryPoints]
[entryPoints.http]
address = ":80"
[entryPoints.http.redirect]
entryPoint = "https"
[entryPoints.https]
address = ":443"
[entryPoints.https.tls]
[retry]
[acme]
email = "me#example.org"
storage = "acme.json"
entryPoint = "https"
onHostRule = true
[acme.httpChallenge]
entryPoint = "http"
Created docker-compose.yml
version: '3'
services:
traefik:
image: traefik
command: --docker
restart: always
volumes:
- /var/run/docker.sock:/var/run/docker.sock
- ./traefik/traefik.toml:/traefik.toml
- ./traefik/acme.json:/acme.json
ports:
- 80:80
- 443:443
networks:
- proxy
container_name: traefik
networks:
proxy:
external: true
And created/started traefik with docker-compose up -dll .
Well - for http it works fine so far - but I am not being redirected to https. And if I would, the connection would be reset (https://cryptpad.mydomain.org -> connection refused).
I checked if something is listening for http/https:
tcp LISTEN 0 128 :::http :::*
tcp LISTEN 0 128 :::https :::*
And tried to telnet it:
[root#cryptpad ~]# telnet localhost 443
Trying ::1...
Connected to localhost.
Escape character is '^]'.
Connection closed by foreign host.
What did I miss?