iOS 15.7.4 (build 19H321) is an official Apple over-the-air update for the iPhone 6s, released on 2023-03-27T17:12:45Z. The update package is 3.02 GB. This is a delta (partial) update that requires 13.6 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: e9037bec54c23a37e1ee4fa74239cd540f2ca42d.zip.