Can you use find my app to locate Apple Pencil?

No.

You will need to look for it the old fashioned way.

If tbe Pencil is within 30 to 50 feet of the iPad, you could try turning Bluetooth on and see if your Pencil appears in the Bluetooth device listings.

At least you would know the Pencil is within 30-50 feet of your iPad.

Sorry & Best of Luck to You!

Your Apple Pencil, unless it is moving, will shut-down its Bluetooth radio after just a few minutes of inactivity - after which it will not be detectable from Bluetooth settings or similar Apps.

The only way to locate a lost Pencil is the Mark #1 eyeball…

Thats sad I wished that they would have an way to make it beep.