iOS 15.7.4 (build 19H321) is an official Apple over-the-air update for the iPhone 6s+, released on 2023-03-27T17:12:53Z. The update package is 3.12 GB. This is a delta (partial) update that requires 13.6.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: bc2d3a1dde8084dc44bb464d1929a1e4879e7d6e.zip.