Ctrl-C and Ctrl-V etc. not working when using RemotePC from Win to Ubuntu

When using RemotePC to remote-desktoping from Win 11 to Linux Ubuntu 22.04 over the web, the keyboard isn't working well, and, in particular, Ctrl-key commands and the like don't work. Despite being officially cross-platform, RemotePC doesn't seem to have a native feature to enable it for Win to Linux. Is there any simple solution that allows using the keyboard properly, incl. sending Ctrl-keys and the like? I've seen resembling questions answered for other RD software such as Remmina, but so far found no solution for RemotePC. I'd like to use RemotePC as it ticks off a few boxes in terms of simple setup & basic features that I've so far not seen all ticked by other RD software (unless some which are even much more expensive than RemotePC).