Using Luna Display in Clamshell Mode
What is Clamshell Mode?
Also known as closed-lid or closed-display mode, clamshell mode allows you to continue using your Mac with the lid closed, while the Mac is connected to another monitor. You can close the lid of your primary Macbook while still being connected to your secondary device using Luna Display.
Using Clamshell Mode with Luna Display
Connect your Macbook to a charger or an external display that can supply power. The Mac will need a power supply strong enough to stay on while the lid is closed.
You might also need to change the settings on the Mac so that the Mac does not enter sleep mode when the lid is closed. Go to System Preferences > Battery, and change "Turn display off after" to Never for both Battery and Power Adapter.