Get access to TrickOrTreat API and check if the plugin is available

if (Bukkit.getPluginManager().getPlugin("TrickOrTreat") != null) {
         
   // Do some stuff...
         
}


int rewards = TrickOrTreat.getAPI().getRewards(PLAYER);
// Returns amount of rewards a player has

int found_doors = TrickOrTreat.getAPI().getFoundDoors(PLAYER);
// Returns amount of found doors by a player

int doors_amount = TrickOrTreat.getAPI().getDoorAmount();
// Returns amount of set doors

boolean open = TrickOrTreat.getAPI().openGameMenu(PLAYER);
//Opens the game menu for a player and returns true or false if succeeded