Accessing admin pages in a Docker image

Disclaimer: I’ve never used Docker…

I’m trying to set up a Docker instance on my QNAP. I installed the image (lucee52-nginx-1 from Docker Hub) using the QNAP Container Station and used all the defaults.

Install went fine and gave me a url to the (32773 is port forwarded to 80) which gives me

# Hello Cruel World!

Lucee released 17 Sep 2018
Apache Tomcat/8.0.53 (java 1.8.0_181) running on Linux (5.10.60-qnap)
Hosted at
## Server Internals
As at {ts '2023-11-08 13:54:37'}
### Environment Variables

So it’s running. Great.

The docs say “The Lucee admin URL is /lucee/admin/ from the exposed port. No admin passwords are set.” but when I try I get an nginx 403 forbidden error.

What am I doing wrong?