iPadOS 12.3 (build 16F5129d) is an official Apple over-the-air update for the iPad Pro 3 (12.9-inch, Cellular, 1TB Model), released on 2019-04-08T17:04:53Z. The update package is 325.77 MB. This is a delta (partial) update that requires 12.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: fac40d2d9373d5f0d08f9b65ba575d68359fbd29.zip.