Yes, iPhone X supports wireless charging, as long as it is placed on the wireless charger, you can give him wireless charging, and wired charging is the same, only the power will be slightly lower, but it is still able to charge, the time will be slightly longer, maybe about two hours, but you can use wired ah is the same. It doesn't matter if it's off or not.
Wireless charging can be used after the iPhone is turned off, that is, it is turned on when it is charged