The actual package name installed is xserver-xorg-input-wacom but this seems to be the upstream package. Working with ubuntustudio 19.10 I have a Huion 610 which has a working pen on session start but the buttons down the side of the tablet just mirror the the mouse buttons and are therefore useless. On an older install I had installed the digimend kernel modules which worked fine but that package also included a file: /usr/share/X11/xorg.conf.d/50-digimend.conf. I added the part of this file that deals with my tablet to the: /usr/share/X11/xorg.conf.d/70-wacom.conf file and I can now use xsetwacom to set buttons and other parameters. It seems that allthough the digimend kernel module has made it upstream to the linux kernel, the xorg config file has not. As the 70-wacom.conf already contains sections for devices other than wacom devices, perhaps the rest of the devices that the kernel supports could be added to that file.
I have attached a copy of my /usr/share/X11/xorg.conf.d/50-digimend.conf file below. At the time the section dealt with two devices: MatchUSBID "5543:006e|256c:006e" but I found that doing a single section for MatchUSBID "256c:006e" worked better for me (in ubuntu 16.04 at the time). The OR-ed version may work fine now.
