Using iPad as photoshop retouch tablet

I set my iPad to mirror photoshop on my iMac, utilizing Sidecar in mirror mode. My Apple Pencil works great with all the tools in the iPad mirrored photoshop workspace. However, when I use a modifier key from the sidebar, such as option or command, they simply don’t work. Can someone offer what

their experience has been. To be clear, I am not using the iPad photoshop program. I am mirroring photoshop from my iMac using the sidecar feature. I have not been able to use the sidebar keyboard and modifier keys. When I open the sidebar keyboard and long press the sidebar option key and then letter “j” it does not duplicate the layer. Instead, it selects the image on the layer.

This a great feature that permits retouching in high iPad resolution without having to buy or lug around an expensive Cintiq. The modifier keys must work though. Perhaps I am not using the modifier keys or sidebar keyboard correctly. Thanks for any helpful comments.