Complain to Huion about their driver.
As long as they don't improve it, you can try and install a Wacom driver on top.
This usually tricks Illustrator into working with your tablet.
Note: it's a hack. It worked for most people, but may or may not work for you.
Please report if it works for you. Thank you.
did not work for me. Huion pro 22 2019, Illustrator 2021 on windows 10.
Please report to Huion.
Ask them if it is supposed to work and if they can guarantee that. Only then someone can investigate how to make it work on your machine.