Interface language localization

I would like to localize the Interface language of Infix Pro (version 6.50) to Czech. I haven’t found an option anywhere to install another language. Does anyone know where I could download it? I wrote to Support a week ago (March 31) but I haven’t received any response.

Infix 7 has CZ and SK langs as this:

It’s already solved. It required installing version 7.3.0. There is a CZ localization available.