Apple released the iOS 16 version last month, and then with iPadOS 16, it made this version available to iPad users with some additions. While iOS 15.7.1 was still in beta, it was reported that some users broke Face ID and the release was delayed. Now, these problems have been fixed and the stable version has been released.
Compatible devices for iOS 15.7.1 and iPadOS 15.7.1
iPhone 6s and later, iPad Pro (all models), iPad Air 2 and later, iPad 5th generation and later, iPad mini 4 and later, and iPod touch (7th generation)
How to install iOS 15.7.
iOS 15.7.1 and iPadOS 15.7.1 update are available for download for iPhone and iPad users with compatible devices. To install the new version on your iPhone, you can access the update by going to Settings > General > Software Update.