How to update my iPhone 6

To update to the maximum of iOS 12.5.7, please see: Update your iPhone, iPad, or iPod touch - Apple Support

And: If your iPhone, iPad, or iPod touch won't update - Apple Support

If the above Apple articles do not help, please post back with relevant information. 

An iPhone 6 isn't capable of 13 or above. To install 12.5.7, use a computer or the Software Update function in Settings; if you encounter a specific issue, describe it in this thread.

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