App Store Connect localizations - missing Serbian language

Hello Experts,

I want to release an app specifically for the Serbian market.
I've chosen Europe->Serbia from Country or Region Availability - it is listed there, everything is okay.
Now I'd like to choose the language for the app, but there is no Serbian under General -> App Information -> Localizable Information:

I'd love to know why is that (whether that's a bug or intended behavior)? And what is the default language for Serbian users in this case?

Unfortunately, the questionmark with useful infos: provides a link, that do not work.

Link is a javascript that effectively does not work apparently: javascript:void(0). I tested on other browsers, doesn't work either. But anyway, that should probably have provided little or no help, just the list of supported languages.

You can add a language only when you create a new version, not on a version already in the store.

So simply create a new version, with serbian localisation and add language for the App in AppstoreConnect.

I hope it would provide information whether or not the Serbian language is supported, this would be enough.

As you can see in the screenshot from my question - it is a new version (and due to that I can select/pick/add new languages). In case of already released apps the selector is restricted to only the chosen/predefined languages (no plus sign available):

Therefore I believe that the Serbian language is just not supported (?), and as far as my research goes, the default language for Serbian users in App Store is English.
So I'll leave it (English) as the only defined option for my app and put Serbian content in it... not a pretty solution, but don't see a better option for now.

App Store Connect localizations - missing Serbian language
 
 
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