Hi all, I notice that on dagster UI, there is a page "playground" where we can store config and launch job. But on the UI I can't figure out how to navigate to that page easily. Any advice?

you mean graphQL playground? Just navigate to /graphql..

If you're thinking about the Launchpad for launching jobs, you can find that after you've selected a job - https://docs.dagster.io/concepts/ops-jobs-graphs/job-execution#dagster-ui