New IPhone 15 cannot update OS

please update via a pc or mac instead

Update your iPhone using a Mac with macOS Catalina or higher

On a Mac with macOS Catalina or higher, you will use the finder in order to upgrade your iPhone. Make sure to Back up your device before starting the upgrade process.

On a Mac with macOS Catalina or later, you will follow the following steps:

1. Open a finder window
2. Connect your device to your Mac via a lighting to usb A or a lightning to usb c cable On the iPhone 15 series, use an usb c to usb c cable.
3. Select your device in the left sidebar of the finder window
4. click general, then click check for update
5. Click download and update.
6. If asked, enter your iPhone passcode

Update your iPhone via a Mac running macOS Mojave or earlier, or on a Windows PC

On macOS Mojave or earlier, or on a windows machine, we won't use the Finder to upgrade your iOS

Instead, we will use iTunes. Make sure to Back up your device before doing any update or upgrade to your phone.

1. Open iTunes
2. connect your device to the computer with an lightning to usb a or a lightning to usb c cable. On the iPhone 15 series, use an usb c to usb c cable.
3. Click device button in the iTunes toolbar
4. In the summary tab, click check for update
5. Click download and update, follow The on screen instructions
6. If asked, enter your iPhone passcode.

Updating/upgrading your iPhone - Apple Community

I had the problem yesterday. I was on the phone with Apple Tech Support and they had me doing the same thing over and over, which would bring me to a screen to Update the OS, and no other choice. So, after we hung up, I went back and tapped on Start Again, which wiped everything off and when I started the process again, I skipped the part where you download apps etc. Then it finally went through and did not try to update the OS. I now have a working iPhone and I am manually downloading my apps. The Apple apps were there when I finished. Good luck.