Updating iPhone 8 Plus iOS

You cannot pick and choose an iOS version. What you get is Settings > General > Software update > [All options are available here]. That is; you need to confirm that your iPhone 8 Plus is compatible with iOS 16.

To check if your device supports new software:

1. Identify your iPhone.
2. Check whether your iPhone model is on the list of compatible devices for the latest version of iOS.

If your device is compatible, then update to the latest version of iOS that is available to you.

If you have a compatible device but your iPhone won't update, try the steps in the article below:

>> If your iPhone or iPad won't update - Apple Support

Hello~ Click on below and review…

If your iPhone or iPad won't update - Apple Support

What happens when you try to update? Once inside the link above you can click on other highlighted tabs of interest. Your iPhone 8 Plus should be eligible for iOS 16 as you asked.See below…

iOS 16 and iPadOS 16 are compatible with these devices - Apple Support

Post back if needed. Take care.

~Katana-San~