Installing on Plesk Onyx using the docker

We’re running Ubuntu 16.04 on an Amazon EC2 instance with Plesk.

I installed Docker and found the image, but have no clue where to go from there… I let it use the default settings and hit run but couldn’t connect to it at all. Ideally, I’d like to just have it run off of a subdomain of one of our domains on the server (chat.example.org) but don’t know if i have to create that subdomain in Plesk, or change DNS settings or something…

I’m also not sure how to use Plesk to get a LetsEncrypt cert for the Docker image (if that’s even possible…)