How to pair Apple Pencil with iPad Air via USB-C?

You should not be using a USB cable to pair your USB-C Apple Pencil. Just to be sure, there are four Apple Pencil models: 1st generation, 2nd generation, USB-C, and Pro. I am assuming you got the USB-C model which is compatible with your 5th generation iPad Air ... correct?

Let's go over the pairing process just to make sure you didn't miss a step.

1. Make sure your iPad is unlocked and awake.
2. Connect the Apple Pencil (USB-C) directly to the iPad’s USB-C port. Don’t use a cable between them. Apple specifically notes the Pencil should plug directly into the USB-C port to pair. Using a USB-C to USB-C cable in between often causes pairing to fail.
3. Once it’s plugged in, you should see a “Pair” prompt pop up on the screen.
4. Tap “Pair” to complete the process.
5. After pairing, you can remove the Pencil. It should now remain connected via Bluetooth. You can now use it wirelessly.