webUSB serial (REPL) doesn't support right click to cut/copy/paste

[rhubarbdog]

I'm trying to transfer printed data from the webUSB serial screen to another package.
I can hold left mouse button to highlight text but cannot right click onto this highlighted text to copy.
Same with just the same with right-click paste (into an input statement)
Also shortcut keys ctrl-X, ctrl-C and ctrl-V don't work

Highlight text and middle-click transfers text from one window to current input point which is a UNIX/Linux thing

uname -a yeilds
Linux samsung01 4.13.0-32-generic #35~16.04.1-Ubuntu SMP Thu Jan 25 10:13:43 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

chromium-browser --version yeilds
Using PPAPI flash.
Chromium 74.0.3729.169 Built on Ubuntu , running on LinuxMint 18.2