I should mention my instructions were for Linux. (NixOS specifically in my case) but no reason it shouldn’t work in other Linux based systems.
@dfabulich I read your post and I think I understand the issue. Port forwarding shouldn’t be necessary. You need the containers IP. 127.0.0.1 is localhost (your local system, not the container)
The jq command should have output a local lan subnet IP you can access without port forwarding.