How to update ios

Here's two different ways to ensure the highest iOS that your phone will support is on your phone.

Update your iPhone, iPad, or iPod touch wirelessly. Click here --> Update your iPhone or iPad - Apple Support

Update your iPhone, iPad, or iPod touch with the Finder on a Mac computer --> Update your iPhone, iPad, or iPod touch with the Finder - Apple Support

What you can do depends upon the exact model iPhone which you do not mention. If it's an iPhone 6 can only update as far as iOS 12.5.6. In fact iOS 14 isn't available any longer and if you have a phone that can upgrade beyond iOS12.5.6 it will go to iOS 15.7.2

An unit running 12.5.6 isn't capable of 13 or above.

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The only iPhones which Apple released 12.5.6 for are the iPhone 5s, 6, and 6 Plus; none of these are capable of 13 or above.

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