A nice digital + stylus pen from ESR which can be used for iPad (2018 or newer).

This ESR Digital + Stylus is incredibly accurate thanks to the very small tip of only 1.4mm. Which makes it an obvious choice for you who are looking for a stylus to draw or work graphically with.

The pen is extremely sensitive to pressure and inclination, so you can easily vary the thickness of the line, create discrete shadows and a wide range of both creative and artistic effects - just like with a regular pencil, but with incredible accuracy.

It is incredibly easy to use, just turn on the button and it is ready to use.
The battery charges quickly and lasts a long time, it only takes 1 hour to charge it, after which it can be used for a full 13 hours before it needs to be recharged.