Every notebook toolbar has a Spark icon that opens the standard Spark Applications UI in a new browser tab. The icon is disabled until your kernel's Spark session is ready — once Spark has started, the icon becomes clickable and takes you straight to the live UI for the application your notebook is running.
What opens is the unmodified Spark Applications UI: Jobs, Stages, Storage, Environment, Executors, SQL — the views Spark itself ships. There is nothing Syntasa-specific layered on top, so anything you've learned about reading Spark's UI in another environment applies here too.
The Spark UI works the same way regardless of how your notebook is set up — on the default kernel, or with a runtime template attached, the button behaves identically once the session is ready.
Access is at the notebook level: anyone in the workspace who can open the notebook can also click its Spark UI. There is no per-user filtering on the live UI.
The Spark UI shows the currently running Spark application. To inspect a Spark application that has already finished — past notebook runs, completed Notebook Process executions — see Spark History Server.