TiltedOnline.exe to start up the mod, either directly or via a shortcut. If everything worked as intended, a Tilted Reverse Console will pop up and the Imgui UI will be displayed on top of your game. Once loaded into a save, run the corresponding server executable (or script, if you created one).
You should now be able to connect in-game by using the UI in the top left corner; pressing RCTRL thrice should free your mouse so that you're able to interact with the UI. The UI is layered on top of one another by default, so you'll need to move the UI windows first to be able to connect.