iOS 12.1.3 (build 16D39) is an official Apple over-the-air update for the iPhone 8 Plus (GSM), released on 2019-01-22T18:09:13Z. The update package is 532.88 MB. This is a delta (partial) update that requires 12.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 286cbcc038cab349c02dd5330f4bb0d75bfe782e.zip.