I did a little research to find an inexpensive graphic tablet with pen that worked on linux as well as other platforms. I found the Ugee m708 was widely available, with good specs and linux compatibility. I bought one on ebay for $40 (pounds actually but i can't find the pound key!!) , unfortunately the dodgy seller only sent the pen and a two finger glove...charming!! Initiated a return on that one!! Second attempt I bought another for $13 from ebay .... this arrived in a box as new!!! Everything works and the app on linux was a doddle to install, with an easy to read bash script which simply copies files and folders to the system. Without the official binary installed it worked anyway. It has buttons which show as a keyboard and mouse, plus it has the pen, which has like 8000+ pressure levels!
It came with a brush and usb A to usb-c and usb micro adapters.
I am using it with ClassIn (windows .exe on wine), which is everything ... multi attendee webcam classroom, with audio (superb audio device selector) and chat, file sharing desktop sharing, etc. Very comprehensive feature set which i am still learning. It's novel feature is a blackboard rather than a whiteboard, which scrolls down for upto 50 boards in a continuous vertical flow. Writing on it with the pen and tablet is a breeze and a pleasure. The only downside is it does require more cpu power than other similar apps....but all features available for free!!
Even just using the pen and tablet as a mouse is pretty good. I might try to replace the cable with bluetooth or some other wireless connection technology.