iPadOS 12.3 (build 16F5155a) is an official Apple over-the-air update for the iPad Pro (10.5-inch, WiFi), released on 2019-05-07T17:03:57Z. The update package is 65.87 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: f1250560817b57986287436d79d3c61a88cb82a4.zip.