@santiago.vidal You have to use the EnvironmentFile, just like all your other environment variables:
https://www.metabase.com/docs/latest/operations-guide/running-metabase-on-debian.html
You cannot just change port to 443. It requires sudo access for ports below 1024. That's how Linux works.
You should use a reverse-proxy like Nginx if you want that to manage certificates.