Telling me I need do update but won’t let me
Telling me I have an error when go use cellular data don’t no where to go to correct issue
iPhone 6, iOS 12
Use the Get Support link at the top of the page here to contact Apple Support. If you have an Apple Store close by, you can make a Genius Bar appointment to have Apple check the iPhone. They will explain your options. Genius Bar Reservation and Apple Support Options - Apple