Actually looks like you extracted the github download directly to steam folder. If you download the zip from github it has a subfolder of ‘Ark-Dev-Kit-release’ which you don’t want. You want the engine folder from that zip to be copied into your steam folder.
In other words to here:
steamapps/common/arkdevkit/Engine/
Not here:
steamapps/common/arkdevkit/Ark-Dev-Kit-release/Engine
Hope this helps!