How to add locked garage to map?

When creating a map how do you add a locked garage to it? I haven't found one in the editor that even has a lock/unlock option. So how is that done?

Check the map-making guide. "If the center of the garage locator is within 64 meters of the active truck (twice as far as the drawn active radius), the garage is unlocked at the start of the map. Otherwise, the garage starts out as locked."