Fall into the void to finish level. You can not drown, you can only pass by triggering the fallTrigger below the map!
By default, when you first loaded the plugin, Fall% mode will be turned on. You can turn it off via the Fall command (type help fall for more information), or navigate to <game directory>/BepInEx/config/com.kirisoup.hff.fall.cfg and change the config.
Your config options will always be saved and remembered when you launch the game at any time.