map keyboard high sierra

Hi - I am on a Macbook Pro 15" Mid 2015 and I updated to High Sierra recently (currently on 10.13.3) and my old keyboard mappings are gone. Is there a way to map Ctrl+Insert to copy and Shift+Insert to paste in High Sierra?

I tried entries in ~/Library/KeyBindings and wasn't able to get anything to take effect.

I also installed Karibiner Elements (not sure if it can do it or not), but even a few simple changes didn't seem to have any effect.

Any suggestions?