tvOS 13.4.5 (build 17L5543d) is an official Apple over-the-air update for the Apple TV 4 (2015), released on 2020-04-15T17:21:33Z. The update package is 125.52 MB. This is a delta (partial) update that requires 13.4 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: b95879762509c53513478abbebdd663c29c23f1e.zip.