Instructions on how to use Cyclone Steam to integrate your MZ game with Steam.
I have created plugins for integrating both Rpg Maker MV and Rpg Maker MZ with steam. Most of the work was done by Greenheart Games (the developers of GameDev Tycoon!), I've simply integrated their work with Rpg Maker.
I've separated the MV and MZ plugins into separate pages because the instructions to use them are a little different, but they both work on similar ways. You can access the download pages through the following links:
For Rpg Maker MZ, use Cyclone Steam.
For Rpg Maker MV, use Orange Greenworks.
The Cyclone plugin has more detailed information about possible errors that can happen if the files are not configured properly. You can check it even if you're using the MV plugin because the errors are the same.