You can quit Arthur VR from the Main Menu:
1. Open Main Menu: To open the main menu, click on the menu button on your controller.
2. Quit Arthur: Click on the red button at the bottom "Quit Arthur" with the Trigger button. You will then quit the Arthur VR application and return to Meta Quest Home.
Alternative:
If you are using the Meta Quest headset, you can also quit Arthur by pressing the Home-button ("o"-button on your right controller), and click on "Close" with the Trigger-button.