Update the PRL (Preferred Roaming List) on your device for the Samsung Galaxy J7 Perx
1. From the home screen, use two fingers to swipe down the Status bar.
2. Tap the Settings icon.
Note: If only one finger was used to swipe down the Status bar, swipe down again to access the Quick Settings menu.
3. Scroll to and tap System Update.
4. Tap Update PRL.
5. The device will search for an update.
Once complete, tap OK.
6. The PRL is now updated.