How do I install the new version
how to install the version
Question marked as
• 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 15
Go to Settings > General > Software Update.
Update your iPhone, iPad, or iPod touch -
https://support.apple.com/en-us/HT204204