iPadOS 12.4 (build 16G5056d) is an official Apple over-the-air update for the iPad mini 4 (WiFi), released on 2019-06-24T17:16:54Z. The update package is 191.45 MB. This is a delta (partial) update that requires 12.4 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 0403581e3b2ae72f6f7723b526f01574331e8c43.zip.