samsung S7 knockoff. it's $18 and I use it more than the Lamy Al-Star.
https://www.amazon.com/Replacement-Samsung-EJ-PT870-Without-Bluetooth/dp/B094XT3BKD
If you have a store like Best Buy near you, you might be able to get a Samsung Galaxy S Pen or Samsung Tab Pen to work as a quick replacement. Or through the (non-affiliate) Amazon links I shared. I haven't used either of them but they are compatible with the Supernote.