Can Unreal autodetect and use more than 1 GPU in your computer?

I have just installed Geforce GT 520 (1 GB) to test and see what is causing the random reboots on my system

I have r9 390 8GB on standby and a 2GB Nvidia Quadro.

If I manage to install all of these GPUs in my system without buying an additional PSU, will unreal be able to use the added GPUs in some manner?

Will Unreal autodetect them or will I need to set them up in unreal settings?

Which GPU should I use for the display monitor and run UE5?

Bump guys any help here. GT 520 is not giving me any rebooting problems. So if I install R9 390 separately on my computer will Unreal be able to detect and use the 8GB VRAM in it?