Tab S10 Ultra S Pen Replacement for Samsung Galaxy Tab S10 Ultra/S10 Lite,Tab S10 Plus Stylus Pen Replacement for Galaxy Tab S10 Ultra/S10 Plus/S10 Lite All Versions S Pen with Nibs(Silver)

What you have is not a real S Pen. I believe that this is the pen you currently have: https://www.amazon.com/Replacement-Samsung-Galaxy-Stylus-Versions/dp/B0DHGPQ534 So you can either but the replacement nibs for this pen (with the claw to remove the nib in your pen) or you can buy a separate tab S Pen.