Make sure your Apple Pencil is compatible with your iPad
Turn on Bluetooth on your iPad
Attach the Apple Pencil to the iPad
Follow the pairing prompt that appears on the screen
Tap Pair
If using Apple Pencil 2nd generation, attach it to the magnetic side of the iPad
If using Apple Pencil USB-C, connect it with a USB-C cable if needed
If pairing does not appear, restart the iPad and try again
If still not working, check that the iPad is updated to the latest iPadOS