defaultLocale is not keeping default lang in Next.js i18n

Question

I'm trying to make my default language in Next.js i18n but always is getting "En" as default language called like fallback.

And I also get this error:

Error: [@formatjs/intl Error MISSING_DATA] Missing locale data for locale: "sq" in Intl.NumberFormat. Using default locale: "en" as fallback

module.exports = {
    i18n: {
        locales: ['sq', 'en'],
        defaultLocale: "sq",
    }
}