Are you trying to paste into the terminal? Since ctrl-c is generally an interrupt, most terminals don’t use that for copying. In my experience, ctrl-shift-c copies, and ctrl-shift-v pastes. So you’d ctrl-c in the browser, then ctrl-shift-v on the terminal to paste.
It seems that doesn’t work with xterm, though, so I’m not actually sure how one might paste in xterm. I normally just use the default GNOME terminal (though I think it also works with Tilix, which PureOS has started including).
Hopefully that’s what you were asking.