You can connect two external displays simultaneously when you close the lid of your MacBook Air or MacBook Pro with M3 chip.
External keyboard and mouse or trackpad
macOS Sonoma 14.3 or later (MacBook Air) or macOS Sonoma 14.6 or later (MacBook Pro)
Display power via USB-C or power adapter with USB-C to MagSafe Cable
Connect an external keyboard and mouse or trackpad.
Connect the Mac to power. If the external display provides power to the Mac, a separate power adapter isn’t needed.
Connect the first display. This will be the primary display, supporting up to 6K resolution at 60Hz (or 4K at 144Hz).
Close the laptop lid.
Connect the second display. This will be the secondary display, supporting up to 5K resolution at 60Hz (or 4K at 100Hz).
Display arrangement preferences are preserved in System Settings.
If you open the laptop lid when both displays are connected, the secondary external display will go dark or disconnect.
If the primary display is disconnected and the lid is opened, then the secondary display becomes the primary display.
The displays must both be disconnected and connected in order to reset the display order.
If your display is connected to a hub or dock and you can use it only to mirror your built-in display, connect your display to a port directly on your Mac.
For more information on connecting displays, see Connect a display to your Mac.