Detecting RCTRL and LCTRL as distinct keypresses in javascript/Pavlovia

I’m porting a Psychopy experiment online.
It successfully uses the RCTRL and LCTRL keys as the two response keys however these don’t appear to register as keys when I run it on Pavlovia. I guess thats just ‘a thing’ and I’ll have to change the response keys but just wanted to double check here, as well as capture it for the record for other users…
thanks
john