Hi All, I hope someone can come up with a solution. I know it is possible and actually very easy to have a multilanguage app which uses system or system-configured language. Is it however possible to have some kind of setting inside the application which would enable user to select the application language in some kind of menu?

First, you must create all the localizable files with the languages you want your app to handle.

Then, you can get the current language on device on first index in UserDefaults.standard.stringArray(forKey: "AppleLanguages"), then wherever you want you can set in your app the new language by setting "AppleLanguages" like

UserDefaults.standard.set(["es-MX"], forKey: "AppleLanguages")
UserDefaults.standard.synchornize()

Once you have the localizable files of all the languages it supports

Why do you not just have a Button for them to change the laugauge of the app in Settings.

Button("Change Language") {
    if let url = URL(string: UIApplication.openSettingsURLString) {
        UIApplication.shared.open(url)
    }
}

This will then open the App Settings and in there is a PREFERRED LANGUAGE section which will set it for that app only. You will get all the other translation etc for free EG(Back button in NavigationView).