Add it to your server
In your server's .ini file (servertest.ini by default), add these to the existing WorkshopItems= and Mods= lines, separated by a semicolon (;).
WorkshopItems=3825951396
Mods=SplitscreenFixes
| Workshop item | Subscribers | Declared in |
|---|---|---|
| Splitscreen Fixes (Split Screen / Local Co-op)3825951396 | 8 | description footer |