Can't get https to work with SITE_PROTOCOL: https

[jcschauer]

I can't get https to work. What am I missing? I tried https://localhost:30080/ and https://localhost:30443/
but they only work (both actually) with http://

from: docker-compose.yml
version: '3.0'
services:
gallery3:
image: bwdutton/gallery3
environment:
#Optional settings for the web server:
SITE_PROTOCOL: https # - set the protocol (http or https) if the default detection doesn't work (useful with proxies)
ports:
- "30080:80"
- "30443:443"