iPadOS 12.1.3 (build 16D5032a) is an official Apple over-the-air update for the iPad Pro 12.9-inch (WiFi), released on 2018-12-19T18:06:43Z. The update package is 210.12 MB. This is a delta (partial) update that requires 12.1.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 96ca472156b18480fc52b6cf9d28de6711ed5bff.zip.