HDMI – CEC Input Switching

I posted this in the Linux subforum, but I dont think it has anything to do with Linux, so I am trying here….

So I want to use CEC to simply switch input sources to the one that Kodi is on when a button on the remote is pushed.

I cant seem to do this. There is a function called CECActivateSource that I see here:
list_of_built-in_functions (wiki)

However, when I assign that to a button on my remote, I get this:

Code:
ERROR: Keymapping error: no such action 'cecactivatesource' defined

How can I get this to work?

Alternatively, if I can get it to switch to kodi when it is currently in screensaver mode, that would work too.