CultureInfo.CurrentCulture always return en-US when publish Asp.net core angular 9 application

Question

I am using localization in my asp.net core angular 9 application. currently I am dealing with two languages (English, German). In controller class I am getting culture info by this globalization method.

    [HttpGet]
    [Route("GetCurrentCultureName")]
    public string GetCurrentCultureName()
    {
        CultureInfo culture = CultureInfo.CurrentUICulture;
        return culture.Name;
    }

If I add German language and get culture in visual studio, it gives "de-De" which is correct, but when publish application it always return "en-US" irrespective of current system language. Please help me.Add Language