Pretty sure they mean your base, since thats what shows on the main map, but unsure...
Try this direct link, perhaps? https://gamekit.com/shop/game/league-of-angels-iii/ Otherwise, like Foxo said, you'll probably have to spend real money.
You can spend gamekit points to buy topaz in game. I believe I paid 1500 pts for mine or somewhere thereabouts. well worth it for the reward of this quest + the next one (next is an easy one: attai...