Why won’t my iPhone update the iOS 15.7.2 ? It will not let me turn on my cellular data on until I update my phone

Hi there jataezhailynn,

If you're seeing an alert on your iPhone indicating an update is required to use cellular data, you'll want to follow the steps in this link to connect your iPhone to a computer to complete the update: If you see a Cellular, Ultra Wideband, or Apple Pay Issue message after an iOS update or restart

Take care.

If the link provided by Sparks0829 doesn’t solve the problem Go to Settings/General/About and look at Modem Firmware. Is the entry blank? If it is you need to reinstall it by restoring the phone to factory settings, then restoring a backup. Back up the phone first, of course:

1. How to back up your iPhone, iPad, and iPod touch - Apple Support
2. Restore your iPhone, iPad, or iPod to factory settings - Apple Support - follow the instructions to restore using your computer, do not using Settings/General/Reset (which is not included in those instructions)
3. Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

If the modem firmware DOES have a value you may have a hardware problem. The first step is what I just posted, but after that you need to contact Apple support using the Get Support link at the top of this page.