I downloaded the zone duplication plugin by Ian from the forum and imported it in the plugin folder of the game. A pop-up showed up saying that I had to restart the game to apply the modification, and done that plugin wasn't anywhere.
The plugin is: https://forum.theotown.com/viewtopic.php?t=20116
Edit: my game is outdated, for now I'll wait for the update to land on Google Play
Edit 2: Got the update, now it seems to work as expected. My fault for not checking the minimum required version...