Touchscreen input on Ubuntu

Hi, just downloaded rack 2.0.3 (2021-12-09) onto my Ubuntu tablet (Ubuntu 20.04.3 LTS),

it works fine but I have the problem that i can’t access the Library to add modules. i have tried long pressing on the screen and using the ‘right click’ button in onboard (onscreen keyboard software)

obviously this really hampers the user experience, by having to plug in a mouse just to add modules.

is there any way we could hook up a long press to opening the library, which input library does rack use anyway?