ENG: The game is noted unavailable on the epic game store, I bought it and there are few and can not download it
I too had problems. Shut off the Epic launcher and then restart it and hopefully/maybe it will allow you to install it then. Imagine if they had an adult that was coding their launcher that could write something like:
on GamePurchase do CustomerLibraryRefresh
The whole Epic process is far from "epic" and closer to "shit". They had lots of launchers to use as references so I don't know why theirs is so terrible. Check in Discord for suggestions or with the clowns at Epic themselves.