To open the in-app menu on Meta Quest devices
Press the menu button on the left-hand controller, or press the right-hand thumbstick.
To open the in-app menu on Steam VR
The exact button will depend on what headset and controller you're using.
Oculus with SteamVR: Y button / B button
Valve Index: B button on either controller
Vive or Windows Mixed Reality: "hamburger" menu button
To open the in-app menu on PICO* devices
Press the menu button on the left-hand controller, or press the right-hand thumbstick.
*PICO is only available in select European and APAC markets