Installing Discourse Behind Reverse Proxy using recommended (supported) installation

Yes, I am using a socket on the local reverse proxy outside of the container, and check, I followed Step 5 in app.yml.

/var/discourse/containers# grep web.socketed.template.yml app.yml
  - "templates/web.socketed.template.yml"

/var/discourse/containers# grep templates/web.ssl.template.yml app.yml
  #  - "templates/web.ssl.template.yml"

/var/discourse/containers# grep templates/web.letsencrypt.ssl.template.yml app.yml
  #  - "templates/web.letsencrypt.ssl.template.yml"

/var/discourse/containers# grep http app.yml

#  - "80:80"   # http
#  - "443:443" # https

/var/discourse/containers# grep DISCOURSE_FORCE_HTTPS app.yml
DISCOURSE_FORCE_HTTPS: true
templates:
  - "templates/postgres.template.yml"
  - "templates/redis.template.yml"
  - "templates/web.template.yml"
  ## Uncomment the next line to enable the IPv6 listener
  #- "templates/web.ipv6.template.yml"
  - "templates/web.ratelimited.template.yml"
  ## Uncomment these two lines if you wish to add Lets Encrypt (https)
  #  - "templates/web.ssl.template.yml"
  #  - "templates/web.letsencrypt.ssl.template.yml"
  - "templates/web.socketed.template.yml"
## which TCP/IP ports should this container expose?
## If you want Discourse to share a port with another webserver like Apache or nginx,
## see https://meta.discourse.org/t/17247 for details
#expose:
#  - "80:80"   # http
#  - "443:443" # https

I reviewed this: Discourse working with jwilder /nginx proxy & acme-companion

but I can’t really make any sense of it in terms of my issue…