Your screenshot is of hover info for a TypeScript declaration, which shows its documentation comment (which is written in the source code and usually copied to generated type declaration files (for TypeScript), or if the JS isn't generated from TS, just in the JS).
I've never seen a library that provides translations for their code documentation comments.
Much more common on the internet and open source world for web libraries is for English to be used as a lingua franca, which might explain why in my (perhaps limited) experience in web dev, I haven't seen anyone put effort into providing versions of their package files with documentation comments translated to various languages.
So unfortunately, it's not something that changing your display language setting can affect.
This probably extends to more than just web libraries. English is fairly well established as the lingua franca of code at least in the open source world. Most of this hover documentation even for other programming lanugages is pulled from documentation comments, which are usually in English, and as already stated, most libraries don't provide header files / documentation sources with translated documentation comments. At least- not that I've observed in my limited experience in the programming world. I'd be happy to be pointed to counterexamples, though!