Thank you for your message. What is the Dell system model in question here?
Was the pen working earlier? Did it stop working after any recent updates or software changes?
Read through this, "Dell Active Pen PN338M Support Center". It shows the compatible systems.
For my reference, please click on the message tab next to your avatar– click “New Message” & search for my Dell username (Dell-Sreejith R) & send a private message with the service tag, registered name & email address.