Where to locate .h files in ide 2

I just tried the right click on a function name, but it doesn't work. I have my functions forward declared. e.g.

int getCurrentAzimuth();

but if I right click (or F12), I just get an error message :

'no definition found for getCurrentAzimuth'

The function getCurrentAzimuth() is defined (as with all others) after the loop() code

The code compiles.

do I need an extension perhaps?

I'm using IDE 2.1.0
cli 0.32.2

thanks.