How can I update my device to iOS 12?
How can I update my iPhone 7 to iOS 12 ?
Question marked as
You can't, your iPhone 7 will be updated to 14.7.1 if you chose to update.
• If you have an iPhone 5S or 6/6plus, the highest you can update to is 12.5.4
• If you have an iPhone 6S or newer, you can update to 14.7.1
Update your iPhone, iPad, or iPod touch -
https://support.apple.com/en-us/HT204204