Drawing tablets tablets are very specific about which pens they work with. Never buy a pen without verifying compatibility first. The best way to confirm compatibility is to contact support.
Usually a drawing tablet is only compatible with the exact pen model it came with
A pen from Manufacturer A will most likely not work with Tablet from manufacturer B.
A pen from Manufacturer A may not work with all tablets made by manufacturer A
Using the same technology such as "EMR" does not mean two pens are interchangeable.
Apple Pencils are only compatible with Apple iPads.
Wacom has so many tablets and and pens that compatibility can get confusing: Wacom pens
If you need to replace a pen, find out the model number that is compatible with your tablet. Then order that exact model. If you don't know the model you need, contact support for your drawing tablet.
Different pens use different resonant frequencies for their EMR signal. So pens that don't use the same frequency as the tablets expect will not be compatible
Different pens use different techniques for transmitting some kinds of information back to the tablet, and these techniques have to also be supported by the tablet to work.
This is sometimes why you can for example try using brand X pen with brand UY tablet, and the tablet might be able to sense the position of the pen, but not the button presses, or pressure.
Driver selectively excludes pens - I know of at least one case with Wacom where the pen and tablet would actually work but the Wacom driver prevents it. The way around this is to use opentabletdriver which does not have that restriction.
Huion's guide to finding compatible pens: (https://support.huion.com/en/support/solutions/articles/44002337828-how-do-i-choose-correct-pen-for-my-huion-tablet-)