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=3806513504;3815957264
Mods=aparosa_BasementDig;aparosa_BasementDigHouseUtilities
These lines include the mod it requires, as its Steam page declares it:
| Workshop item | Subscribers | Declared in |
|---|---|---|
| Basement Building: Utilities for Player-Built Houses [B42.21.0] [SP/MP]3815957264 | 414 | description footer |