Enchantment error

It's because Item::addEnchantment() doesn't return the item instance (unlike setCustomName(), setLore(), etc..).
You need to use:

PHP:

$item = Item::get(Item::STICK);
$item->addEnchantment(...);
$player->getInventory()->addItem($item);


Also, small tip: You can specify multiple 'Item' parameters to Inventory::addItem().

PHP:

$inventory->addItem(
    Item::get(Item::STICK),
    Item::get(Item::STONE),
    Item::get(Item::BONE)
);


 

Thanks!