Apple Pencil is not charging

Sorry, but it may be too late. Rechargeable lithium batteries, not just those used in the Apple Pencils, if left nearly or fully depleted for long periods of time (2 years would qualify), will lose their ability to be charged again.

AFAIK, Apple does not replace these batteries, and if you wish to continue using an Apple Pencil, you will need to get a new one.

The battery may have degraded. Try connecting it directly to your iPad or using the appropriate charger for a while. If it still doesn’t charge, you may need to contact Apple Support, as the battery may need replacement.