To Run
Need to add steamworks sdk 1.55 which you can download here https://partner.steamgames.com/downloads/list.
- Extract files to root directory C:/
- click on the steamworks file under the steamworks folder in the gamemaker gui
- Under build options, point towards the extracted 'sdk' folder in your root folder
Documentation for steam extension https://github.com/YoYoGames/GMEXT-Steamworks/wiki