iOS 12.1.3 (build 16D39) is an official Apple over-the-air update for the iPhone 8 Plus (GSM), released on 2019-01-22T18:09:10Z. The update package is 1.55 GB. This is a delta (partial) update that requires 11.2.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 5dc347fd39e7f49af816eb72bb26abe0c2ec6687.zip.