Because that's only possible with Lua. What you could do is assign a number instead & at begin of scene you could use the if lua result action part or execute a script action part, to check the language & update the values as needed.
I would probably do something like this...
execute a script:
Values["example"].Int = game.StandardLanguage:getId().id
What you are essentially doing there is telling it to set the integer value to whatever the ID value of the language is. The first language you create will be 0, then 1, & 2, & so on. It just keeps on incrementing. If you aren't sure what ID belongs to which language, you can right click on a language in the list & select copy id. Paste them into a notepad or something so you can keep track of them.
Alternatively, if you want you could create a table manually & use that instead.
execute a script:
local t = {
English = 1, German = 2, French = 3
}
Values["example"].Int = t[ game.StandardLanguage:getName() ]
That's 2 methods out of multiple other solutions that are probably available.