You charge Apple Pencil (2nd generation) differently from Apple Pencil (1st generation). Find out which Apple Pencil model you have, if you're not sure.
If you have Apple Pencil (2nd generation)
Attach your Apple Pencil to the magnetic connector on the long side of your iPad.
If you don't see the charge status appear for a moment near the top of the screen, make sure that Bluetooth is turned on.
If you have Apple Pencil (1st generation)
Plug your Apple Pencil into the Lightning connector on your iPad. You can also charge with a USB Power Adapter by using the Apple Pencil Charging Adapter that came with your Apple Pencil.
Apple Pencil will fast charge when plugged into either power source.
Check the charge status
When you attach an Apple Pencil (2nd generation) to your iPad, you see the charge status on the screen for a moment.
To see how much charge your Apple Pencil has left while you're using it, check the Today View on your iPad. Just swipe from left to right on the Home screen or Lock screen.
If you're charging your Apple Pencil (2nd generation) with your iPad Pro and your car's keyless entry device (key fob) is nearby, signal interference might prevent you from unlocking your car with your key fob. If this happens, you can simply move your iPad Pro away from the key fob or remove your Apple Pencil from your iPad Pro and store it separately. When Apple Pencil is finished charging, any resulting signal interference will cease.