macos – iPad as Mac Display: How to return to Mac desktop from iPad home screen?

I’m using my iPad as a secondary display. The menu bar icon on my Mac is blue (active), my Mac desktop is on the iPad.

I press the iPad’s home button. I’m now on the iPad’s home screen. The Mac is still connected, the menu bar icon is still blue.

How can I quickly return to viewing my Mac desktop on the iPad?

Thanks!