Missing StreamDeckSDK.lib on Build

[rombust]

When building this example:
C:\Development\streamdeck-cpu\Sources\out\build\x64-Debug\ninja : error : 'StreamDeckSDK_build-prefix/lib/StreamDeckSDK.lib', needed by 'cpu.exe', missing and no known rule to make it

I assume the actual official C++ SDK is found elsewhere ? I cannot find it.

The readme.md says : CPU is a sample plugin demonstrating the Stream Deck SDK - https://developer.elgato.com/documentation/stream-deck/

However this page no longer exists. Looking at the single current pull request, this link is removed. This is a bit worrying.

Looking at: https://github.com/fredemmott/StreamDeck-CPPSDK . "This is re-usable library derived from Elgato's CPU plugin. This contains the C++ files, and can be built (including StreamDeckSDK.lib)

Where is the official StreamDeckSDK.lib code?