How to access this service container by port number

[Si]

I have some local testing with docker containers, and I'm trying to replicate it in bitbucket pipelines. I have the following in my pipelines definition:

definitions:
  services:
    chrome:
      image: previousnext/chrome-headless
      ports:
        - "9222:9222"

 And I understand this should make it available on localhost:9222. But when the tests run, I get...

Could not fetch version information from http://localhost:9222/json/version. Please check if Chrome is running.

 I'm not sure how to debug. I don't even know if the container is running.  I have also tried simply

chrome:
 image: previousnext/chrome-headless:65

[Si]

I fixed this by using the service in my step with:

services:
  - chrome

[Si]

nevermind. I just ran the docker command directly.

[Si]

I unaccepted this answer, i have other issues with memory running docker containers in steps, and I believe I should be using service definitions.