Oh ok
I often use documentation from https://wiki.archlinux.org because it’s often well detailled and more complete than documentation I can found on Debian sites 
That’s strange… on my side to be able to configure my 13.3 the only thing I was able to found was about the 15.6 (there’s just few modification to do for a 13.3 as USB HID is not the same)
No
Using the wacom driver for your XPPen tablet doesn’t allows the configuration through KDE interface, only Wacom tablet are supported by the interface.
To be able to use my XP Pen Artist 13.3 on Debian, I had to:
- create specific udev rules to let the system recognize buttons
- create specific xorg.conf configuration
- create a shell script executed at session startup to map buttons
Ok 
So I can provide you what I’ve made on my side
Technical details
Before starting, check your tablet:
$ lsusb
Would provide something like this in list:
Bus 009 Device 002: ID 28bd:000b
the tablet is not named, you have to know the HID (for a 15.6 i think that HID is28bd:000cso you have to change 000b by 000c everywhere in configuration)
The udev configuration
File /etc/udev/hwdb.d/10-xp-pen-keyboard.hwdb
evdev:input:b0003v28BDp000B*
KEYBOARD_KEY_d0045=332
File /etc/udev/rules.d/67-xorg-xppen.rules
KERNEL!="event[0-9]*", GOTO="xppen_end"
ENV{ID_VENDOR_ID}=="28bd", ENV{ID_MODEL_ID}=="000b", ENV{x11_driver}="wacom", KERNEL=="event8", SYMLINK+="input/xppen-pad", NAME="XP-PEN ARTIST 13.3 pad"
ENV{ID_VENDOR_ID}=="28bd", ENV{ID_MODEL_ID}=="000b", ENV{x11_driver}="wacom", KERNEL=="event7", SYMLINK+="input/xppen-stylus"
LABEL="xppen_end"
To know the event number, do the following
$ sudo evtest
You should get in list something like this:
/dev/input/eventX: XP-PEN ARTIST 13.3 Mouse
/dev/input/eventY: XP-PEN ARTIST 13.3
/dev/input/eventZ: XP-PEN ARTIST 13.3
Note: the event number may change…
And then
$ sudo udevadm info -a /dev/input/eventX
Would provide you all information needed to eventually update your udev configuration files for XP Pen Artist 15.6
The XOrg configuration
File /etc/X11/xorg.conf.d/12-xppen-tablet.conf
Section "InputClass"
Identifier "Tablet0"
MatchUSBID "28bd:000b"
MatchDevicePath "/dev/input/event*"
MatchIsTablet "on"
Driver "wacom"
# note: to define these parameters properly, you can use xinput_calibrator tool
# that provide an interface to calibrate the pen and then provide XOrg configuration
# to apply
Option "MinX" "168"
Option "MaxX" "29238"
Option "MinY" "-36"
Option "MaxY" "16529"
Option "SwapXY" "0" # unless it was already set to 1
Option "InvertX" "0" # unless it was already set
Option "InvertY" "0" # unless it was already set
EndSection
Section "InputDevice"
Identifier "XP-PEN ARTIST 13.3 pad"
Driver "wacom"
Option "Device" "/dev/input/xppen-pad"
Option "Type" "pad"
EndSection
File /etc/X11/xorg.conf.d/32-xppen-monitor.conf
Section "Monitor"
# HorizSync source: unknown, VertRefresh source: unknown
Identifier "Monitor1"
VendorName "XPPen"
ModelName "UGD Artist 133"
HorizSync 31.0 - 70.0
VertRefresh 59.0 - 61.0
Option "DPMS"
EndSection
File /etc/X11/xorg.conf.d/42-xppen-graphic.conf
Section "Device"
Identifier "Graphic1"
Driver "nvidia"
VendorName "NVIDIA Corporation"
BoardName "GeForce GT 630"
BusID "PCI:3:0:0"
MatchSeat "seat-1" # Needed when only configuring part of Xorg for non-seat0.
EndSection
Note: I’m in a multi seat configuration so, comment/remove the MatchSeat if you’re not in multi-seat config (or replace it by seat0 that should be the default seat I think)
File /etc/X11/xorg.conf.d/62-xppen-layout.conf
Identifier "seat-1"
Screen "Screen1" 0 0
InputDevice "Keyboard1" "CoreKeyboard"
InputDevice "Mouse1" "CorePointer"
#InputDevice "Tablet0" "SendCoreEvents"
InputDevice "XP-PEN ARTIST 13.3 pad"
Option "Seat" "seat-1"
Option "SingleCard" "on"
Option "AllowEmptyInput" "true"
Option "AllowEmptyInitialConfiguration" "true"
Note: I’m in a multi seat configuration so, comment/remove the Seat if you’re not in multi-seat config (or replace it by seat0 that should be the default seat I think)
Apply changes
When udev and xorg conf are modified, you can apply change without having to reboot with:
$ sudo udevadm control --reload
$ sudo udevadm trigger
$ sudo systemctl restart display-manager
Note: udev symlink must be defined before XOrg configuration is updated as the xorg configuration refers to symlink /dev/input/xppen-pad defined here
The shell script executed at startup session
#!/bin/sh
xsetwacom set "XP-PEN ARTIST 13.3 pad" button 1 key tab
xsetwacom set "XP-PEN ARTIST 13.3 pad" button 2 key f10
xsetwacom set "XP-PEN ARTIST 13.3 pad" button 3 key alt
xsetwacom set "XP-PEN ARTIST 13.3 pad" button 8 key f12
xsetwacom set "XP-PEN ARTIST 13.3 pad" button 9 key shift
xsetwacom set "XP-PEN ARTIST 13.3 pad" button 10 key ctrl
xsetwacom set "XP-PEN ARTIST 13.3 stylus" area 233 -38 29395 16486
xsetwacom set "XP-PEN ARTIST 13.3 stylus" button 1 1
xsetwacom set "XP-PEN ARTIST 13.3 stylus" button 2 2
xsetwacom set "XP-PEN ARTIST 13.3 stylus" button 3 3
echo "Tablet: Pen: "
echo " "
echo "+---+ _ "
echo "| 1 | (tab) | | "
echo "+---+ | | "
echo "| 2 | (f10) | | "
echo "+---+ | | "
echo "| 3 | (alt) | | "
echo "+---+ | | "
echo "| 8 | (f12) |o| <-- [right] stylys.3 (button 3 = right) "
echo "+---+ | | "
echo "| 9 | (shift) |o| <-- [middle] stylus.2 (button 2 = middle)"
echo "+---+ |_| "
echo "| 10| (ctrl) \ / "
echo "+---+ v <-- [left] stylus.1 (button 1 = left) "
You have to install the xsetwacom utility for this.
I don’t remember how I was able to determinate which button number match with which physical button (maybe evtest…)
I think I provided practically everything I know about the subject…
There’s something missing in my documentation.
I think I’ve used digimend, but I may have installed xf86-input-wacom instead.
Don’t remember this part, I only took notes on all complex configuration files and action needed to have my tablet perfectly working…
I have to check packages installed on my computer and update my documentation
Grum999