iPadOS 13.4 (build 17E5255a) is an official Apple over-the-air update for the iPad Pro 12.9-inch (WiFi), released on 2020-03-10T17:21:01Z. The update package is 728.33 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: 18990bfa69332ec7a6ee3367b3884927dac783c5.zip.