I'm trying to develop an Android APP that manages telephony services.
One of the first tasks I tried to implement is getting info from the phone/SIM.
In https://developer.android.com/reference/kotlin/android/telephony/TelephonyManager (Kotlin) i can find the methods of the class and I see the getNetworkCountryIso() method to retrieve this info.
Somewhere in Internet I found an example of code that doesn't use this method but uses a prorpiety-like format:
val tm = getSystemService(TELEPHONY_SERVICE) as TelephonyManager
val networkCountryISO = tm.networkCountryIso
Where can I find this way to retrieve info?