Runner service: token access

selenium:
  stage: test
  services:
    - name: mono
      alias: xsp
      entrypoint: ["/bin/sh", "-c", "echo token is $CI_JOB_TOKEN"]

The service container prints out an empty string. How can I get access to this token from within the service?

I want a service to act as a web sever and run my project so that I can run functional tests against it. I figured the easiest way to do this would be to clone the code when the service starts, but without a token I don’t see how.

Is there some volume mount I can get access to which has a checked out copy of the codebase?