You may encounter the pop-up of HuionTablet needs access to accessibility after installing the driver. Actually you have already ticked it, but it still keeps asking you to do that.
The root is you don't properly uninstall the driver before reinstalling it.
Please refer to the following steps:
1. Go to HuionTablet-Preferences
2. Click on "Uninstall" to uninstall current driver
3. Go to "Security & Privacy"
①click on "Accessibility"
③click on "-" to delete it
4. Reinstall the driver according to the article below: