iOS 13.4 (build 17E5233g) is an official Apple over-the-air update for the iPhone 6s, released on 2020-02-19T18:24:54Z. The update package is 782.34 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: 1228e7d6bd10d17ef108102f07176e78c31c14b3.zip.