Unfortunately with that there's not a lot we can do to help, other than ask you to test a couple things:
Test your S-Pen on another phone. Does it work there? If not, your pen is damaged and needs to be replaced. If the pen works in another phone, chances are the digitizer used for the S-Pen is damaged or disconnected. BUT it could also be that the phone doesn't detect the pen is 'out' and activates the digitizer (there's an option to keep the digitizer always on...use that and see if it helps; if it does, then the sensor to detect the S-Pen has been removed is damaged. Lastly, I'd try another phone's pen on your device.
06-06-2018 04:07 PM