How can you manually trigger a task or pipeline in GitLab through the user interface?

In GitLab, to manually run a job or pipeline through the user interface:

1. Go to the project and open the CI/CD > Pipelines section.
2. Find the desired pipeline or create a new one.
3. If a job with the parameter when: manual is defined in .gitlab-ci.yml, a Play button (▶️) will appear next to it.
4. Click this button to manually start the job.

If you want to run the entire pipeline manually, you can click the Run pipeline button at the top of the Pipelines page, select the branch and parameters, then confirm the run.