GUI text kerning?

I’m sure I’m missing something obvious, but how do I adjust the kerning in my imported fonts? I see the option there in the inspector when I select it, but it’s greyed out. – is that a pro feature or something? I’m using indie iPhone basic.

thanks in advance

AFAIK, kerning is set by the font importer based on the font metrics in the font file and is not something that can be controlled.