iOS 13.4 (build 17E5233g) is an official Apple over-the-air update for the iPhone 6s+, released on 2020-02-19T18:24:56Z. The update package is 328 MB. This is a delta (partial) update that requires 13.4 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: f7976272cc9ac3ef53dc00029960bca1661061a2.zip.