MPS facet does not run

Hello,

maybe someone here can give me a hint.

I'm trying to add a custom action to the build process. This means that I want to run a specific action after the textgen of language X ran.

I got a hint to use a build facet. When I build the model which uses language X the build facet never gets triggered.

Is my configuration wrong? Or is there a even a better solution to my problem using another method?

Thanks for your consideration!