Version-4
1. Open Settings on your phone.
2. Go to “Apps,” then tap on “Special app access.” If you don’t find it, go to “Advanced” followed by “Special app access.”
3. Tap on “Install unknown apps.”
4. Tap on the app you will use to install the third-party apps. This is usually a browser or the Files app. We’re using Chrome for this example.
5. Enable the toggle next to “Allow from this source.”
6. Tap on the APK file to install it.