iOS 15.7.4 (build 19H321) is an official Apple over-the-air update for the iPhone 6s, released on 2023-03-27T17:12:44Z. The update package is 3.16 GB. This is a delta (partial) update that requires 13.1.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 763681cc57916f839769ccec770e34a17264518a.zip.