iOS update
How do I change or update my iOS 12.3 to iOS 13.0?
Earlier iPhone models
Question marked as
If you have an iPhone 6, 5s, or 6 Plus, your phone cannot be updated to anything higher than 12.5.7. It lacks the necessary hardware. If you have a newer iPhone, You can try updating by selecting Settings > General > Software Update. If your phone is eligible for an update, you will be prompted to do so. Read more about it here:
Update your iPhone or iPad - Apple Support