iPadOS 12.3 (build 16F5139e) is an official Apple over-the-air update for the iPad Pro 2 (12.9-inch, Cellular), released on 2019-04-22T17:08:19Z. The update package is 381.62 MB. This is a delta (partial) update that requires 12.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: de6923f31f343dff3f1473f8b1c1d9a2ce2e85bf.zip.