You need Clickteam Fusion 2.5 Developer (not the standard version). The Steamworks object is locked to the Developer edition due to the complexity of the API.
If you're a game developer using Clickteam Fusion 2.5 (or its predecessor, Multimedia Fusion 2) and planning a Steam release, you've likely encountered references to the steamworks.mfx file. This extension is the official bridge between Clickteam Fusion and the powerful Steamworks API. steamworks.mfx download
There are several reasons why you might need to download steamworks.mfx: You need Clickteam Fusion 2