These are the instructions for Khadas Edge V to flash:
Get a USB C Male to USB A Male cable.
Then connect the USB cable to the top USB C port on Khadas Edge V and the other end to a USB port on your PC(avoid USB Hubs as they can cause problems).
Then press the middle button on the side(Function button) and hold it in, now press the button after it, first button towards you(Reset button), after 2 seconds release the first button.
(This is if the buttons are on the left side and the ports are facing towards you, if the buttons are on the right side and the ports are facing backwards then the 'Reset button is the last on on the right back side)
If you have AndroidTool open on a PC, it will say ‘Found Loader Mode’.
Now do ‘EraseFlash’, it is needed every time if you flash between different Android OS’s, but not the same OS.
Now click ‘Upgrade’.
After it finishes, wait 10 minutes or so before removing the USB cable and unplugging it.
It should now boot Android Pie.