Using MBP with External Monitor in Clamshell Without Power Adapter

Just bought a Samsung M5 monitor that is AirPlay compatible. Using it with my 2020 MBP with the lid closed works flawlessly as long as the power adapter is connected to the MBP. Unplug the adapter and I lose the monitor. What sort of black magic can I do in order to make this work without needing to be plugged in? Thanks.