Update my iPhone

For reference, see here:

Update your iPhone or iPad - Apple Support

As Servant of Cats explained, the latest update has apparently been paused.

Then update your iPhone, once Apple fixes the issues with the updates they put out the other day (updates that in some cases, are currently "on hold"). We cannot update your iPhone for you.

Note that the iPhone 8 Plus listed in your tag line can only update as far as the latest release of iOS 16. You cannot update it to iOS 17, 18, or 26, if that might be what you are asking about.

What happens when to tap Settings > General > Software Update?

If an error message appears, what is the exact message?

What ios is your Iphone 8 plus on?

The update has been paused for iOS 16.7.13, however, it is not a critical update. It replaces an expiring security certificate. It is safe to wait a couple of days until Apple releases it.

https://www.macrumors.com/2026/01/28/apple-stops-signing-newly-released-ios-updates/