public void openGUI(Player p) {
    List<String> items = new ArrayList<>(data.getConfigurationSection("items").getKeys(false));
    Inventory inv = Bukkit.createInventory(null, 9, "Названьице");
    for (String s: items){
        ItemStack item = new ItemStack(Material.getMaterial(s.toUpperCase()));
        item.getItemMeta().setDisplayName(data.getString("items."+s+".name").replace("&", "§"));
        item.getItemMeta().setLore(data.getStringList("items."+s+"lore"));
        inv.addItem(item);
    }
    p.openInventory(inv);
}