I am not sure about windows 10 build number, but can provide a way to get word host full version on desktop platform.
Generally, following solution will work,
const context = window.external.GetContext() context.GetHostFullVersion()
But in some of the cases, where add-in opens in iframe, it needs accessed by following way,
const context = parent.window.external.GetContext() context.GetHostFullVersion()
I have tried this on windows platform, this will provide you version string like “16.0.13328.20292”.
CLICK HERE to find out more related problems solutions.