觸控螢幕小鍵盤

1. Install it: sudo apt install onboard
2. Once you've installed onboard, press Super (Windows key) and then type "onboard" to see both the "onboard" and "onboard settings" options. Use the first to bring up the program and the latter to modify its settings.
3. Here's a screenshot. It seems to work ok:

Also note the little icon in the top right of the screen you get to it now too:

https://askubuntu.com/questions/1057485/ubuntu-18-04-no-on-screen-keyboard