iPadOS 13.4 (build 17E5223h) is an official Apple over-the-air update for the iPad Air 2 (Cellular), released on 2020-02-05T18:16:55Z. The update package is 704.77 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: b190bfdae515c16d2a3e5094f0d55012409a0a93.zip.