Apple pencil with ipad mini

Make sure the tip of the Pencil is screwed on securely and snugly ( NOT TOO tight! ).

Then follow all of the troubleshooting tips in this Apple Website Webpage support article.

Tap the link below.

https://support.apple.com/en-us/HT205236

Best of Luck to You!

Here is one of the better troubleshooting guides:

https://appletoolbox.com/apple-pencil-not-working-heres-our-troubleshooting-guide/

Be aware that if your Pencil has been set-aside for an extended period, unused and uncharged, the Pencil battery may now be irretrievably damaged through deep discharge. In common with all Li-ion batteries, they must always have some level of charge.