To install ThievesIsland on the server, you must do the following:
1. Click install mods, in the mod ids box enter the ThievesIsland mod id (651147582) and then click execute.
2. Next, go onto the command line manager and click new command line.
3. Give the command line a name in the Description box, then enter Thieves into the map box and tick the box next on the left.
4. Then just save that command line, and click the select button on the right of it.
5. ThievesIsland should now be installed just start the server and get playing.