Since you are downloading the APK from a third-party source (it is not available on the Google Play Store), you must allow installation from unknown sources.
For Android 4.2.2, look for or older. Newer versions (2.0+) may require Android 5.0+. The file size is typically 10–15 MB. download kingo root apk for android 4.2.2
Open the browser on your Android 4.2.2 device. Navigate to the official Kingo Root website (kingoapp.com) or a trusted APK mirror repository. Look for the "Android Version" download button. Since you are downloading the APK from a