iPadOS 12.3 (build 16F5155a) is an official Apple over-the-air update for the iPad 6 (WiFi), released on 2019-05-07T17:03:58Z. The update package is 400.96 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: fc5aeed1e482a0593d5b7ed94ed7f482a0fce568.zip.