Apple Pencil for iPad Pro 12.9 and Duet Pro with MacBook Pro Running Catalina

Since Duet Display/Duet Display Pro are not Apple products, you would need to contact the developers of Duet Display for any issues with their software/application products.

Also, Duet Display Pro has NOT been designed from the ground up to be a graphics tablet app to be used with iPad and Mac.

For a “from the ground up” graphics tablet app for iPad and Mac, look at Astropad Standard OR Astropad Studio.

‎Astropad Standard on the App Store

‎Astropad Studio on the App Store

Best of Luck to You!

Duet is not meant for controlling your computer or anything on your computer. It’s a program that lets you use your iPad as a second monitor only. This allows you to have your iPad work as if there was an additional monitor that you connected to it and would be controlled by a mouse and keyboard. You are controlling the computer and simply using the display on the iPad as a screen for the computer. Therefore, you will not be able to control the computer by way of touch or pencil on the iPad.

I am using older version of Astropad that still works with my older MacOS versions and my own choice of compatible third party stylii.

Astropad has always been design to be the premium graphics tablet-like app for iPad.

I have been using Astropad on my iPads from the day Astropad was initially introduced back in 2014.

Only Apple Sidecar beats Astropad, but Astropad is really the only alternative for use with older Macs NOT compatible with the Apple Sidecar feature.

I use an older version of Astropad that is compatible with my older Mac OS and a third party stylus that are both compatible with my older iPad Pro and with my older version of Astropad.

I use older versions of Photoshop, Painter and AutoDesk Sketchbook with Astropad.

All works fine.

You'll find plenty of YouTube videos that showcase drawing with Astropad and Apple Pencil with different drawing apps.

Best of Luck to You!

Actually you are mistaken.

Duet Display Pro actually has features that make it act as a graphics tablet and has the “Pro” features that are for Apple Pencil/graphics tablet use.

Lots of YouTube videos show drawing with Apple Pencil and Astropad, too!