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=3619862853;3807686870
Mods=ZombieBuddy;None (manual download)
These lines include the mod it requires, as its Steam page declares it:
- ZombieBuddy ·
ZombieBuddy
| Workshop item | Subscribers | Declared in |
|---|---|---|
| [B42] ZombieBuddy Extensions3807686870 | 224,054 | description footer |