Right so enter the position and this code should work for you. This uses this sleep class: 
 
	 
 
	 
 
		Position shop = new Position(###,###,###);
		if (myPlayer().getPosition().distance(shop) > 10) {
			WebWalkEvent event = new WebWalkEvent(shop);
			execute(event);
		}
		NPC ShopKeeper = npcs.closest("Shop keeper");
		if (ShopKeeper.exists()) {
			if (ShopKeeper.isVisible()) {
				if (!store.isOpen()) {
					ShopKeeper.interact("Trade");
					Sleep.sleepUntil(() -> store.isOpen(), 5000);
				}
			}
		}
		if (store.isOpen()) {
			if (!inventory.contains("Spade")) {
				Sleep.sleepUntil(() -> store.buy("Spade", 5), 5000);
			}
		}