cldr-localenames-full/main/prg/languages.json

Translated versions of locale display name elements: languages, scripts, territories, and variants. (all locales)

{
  "main": {
    "prg": {
      "identity": {
        "version": {
          "_cldrVersion": "44.1"
        },
        "language": "prg"
      },
      "localeDisplayNames": {
        "languages": {
          "en": "ēngliskan",
          "prg": "prūsiskan"
        }
      }
    }
  }
}