Hello and welcome,
They indeed have a linux driver here
https://www.xp-pen.com/download-299.html
But on Manjaro you will need a PKGBUILD to install it. Gladly someone already made one and you find it in AUR.
https://aur.archlinux.org/packages/xp-pen-tablet/
To install it, run this commands from terminal:
sudo pacman-mirrors -f && sudo pacman -Syyu base-devel xorg-xinput
then
pamac build xp-pen-tablet
Reboot the system after that. Then open up terminal and provide:
xinput list
Use ``` above and bellow the output text when you paste it here, for proper formatting.