iOS 12.1.3 (build 16D5032a) is an official Apple over-the-air update for the iPhone 8 Plus (GSM), released on 2018-12-19T18:06:56Z. The update package is 333.74 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: f816b6ff19f5f1b2a3042a1a2b6fd1aba217279d.zip.