Who to update my iPhone 6

iOS 12.5.7 is the most current version an iPhone 6+ can update to. It cannot run iOS 13 or later.

If it's not already running that, go to Settings ➜ General ➜ Software Update.

click here ➜ Update your iPhone or iPad - Apple Support

An iPhone 6 Plus isn't capable of 13 or above; they require at least 2GB of RAM. To install 12.5.7, use a computer or the Software Update function in Settings.

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