Gitlab-runner config file

I am hoping to get a quick answer as to how I set up the /etc/gitlab-runner/config.toml for a specific shared runner on my project CI.

Basically, I need to know how I link a specific runner in the .toml file to the runner being used on GitLab, and I then need to change the output_size variable. Right now. under [[runners]] I have given an arbitrary name, I am using the token that is provided on the GitLab Settings > CI/CD page under “Runner” for my project (shared runner token), and I have my URL set to the IP where GitLab is hosted.

Do I have to put /ci/ at the end of the URL? And/or am I using the wrong token? If so, how do I find the correct token? I have tried a number of iterations of these variables, but no matter what it seems like after I change the output_size and do a gitlab-runner restart, the output size is still capped at 4092.