iOS 13.3.1 (build 17D5050a) is an official Apple over-the-air update for the iPhone 11 Pro, released on 2020-01-22T18:07:26Z. The update package is 130.03 MB. This is a delta (partial) update that requires 13.3.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 30009598081a4476389e9db4bd84e855c0f6580f.zip.