I gave my daughter my old iphone 6 just for her to play on. It is no longer activated (hasn't been in over a year)and she was just using the phone with WiFi. Recently she updated the phone to iOS 13 and now it's asking her for a PUK code. She didn't lock it because she ws playing on the phone just fine before the update. I am not sure how to fix this because I don't have another sim card. Please help.