You can charge your iPad as usual by connecting your USB-C cable to the USB-C port on your iPad. Or you can connect your USB-C cable to the USB-C port on your Magic Keyboard. Your Magic Keyboard doesn't need to be charged.

Find out what to do if your iPad Pro doesn’t charge when it’s connected to your Magic Keyboard.

The USB-C port on Magic Keyboard provides power, but it doesn't transmit data. This means you can't use this port with an input device such as a USB-C mouse. Never connect one end of a USB-C cable to the USB-C port on your iPad and the other end to the USB-C port on your Magic Keyboard.