iOS 13.4 (build 17E5249a) is an official Apple over-the-air update for the iPhone 6s+, released on 2020-03-03T18:20:16Z. The update package is 712.27 MB. This is a delta (partial) update that requires 13.3.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 7708f09d8545d8199a9b9c5e2bbb3b4e9228f72d.zip.