iPhone 14 ios 16.3.1 will not install

To update over the air from the phone all of these requirements must be met:

• You need at least 10 GB of free storage for iOS 16 or 6 GB for iOS 15 or lower; more is better
• You must be connected to a Wi-Fi network (and not a personal hotspot) unless it is an iPhone that supports cellular 5G (12, 13, 14 or SE 3rd edition) and has a 5G network connection
• The phone must be charged to at least 50%, and preferably plugged in so it stays above 50% during the update
• The phone must not be in Low Power Mode
• The phone must not be connected through VPN, and it may be necessary to delete any VPN apps and VPN profiles
• The phone cannot be in Airplane mode and must have a cellular data connection
• You cannot still have a beta version installed on the phone
• You cannot have a previous version that was downloaded, but not installed - go to Settings/General/iPhone Storage to look; if you find an iOS installer, delete it

If you can't meet all of them you can still update using your computer.

Make sure you are connected to WiFi, or have a 5G connection, and also connect a charger to your iPhone.

Go to Settings > General > iPhone Storage

If you see an iOS Software Update, tap in and delete it.

Then go to Settings > Display & Brightness > Auto Lock

Set Auto Lock to Never (Remember to put this back after updating!)

Now restart your iPhone. After go to Settings > General > Software Update.

Select Update. Leave your iPhone with the screen on, connected to WiFi and charger, and wait.

When you see Install Now, tap and wait for your iPhone to update.

Try connecting to a charger and restart your iPhone. Then go back and try again. Have you removed the update and started over as described in my first answer?

If your iPhone is low on battery, it must be connected to a charger. If you use a Wireless Charger, then in some cases you can only update when the phone is at 50%.

How are trying to do this? Any error message?

Perfect.