The software you bought from Costco is desktop software. You cannot use desktop software on an iPad. Desktop software only works on a full PC or Mac. Did you not read the system requirements? See if you can return it to Costco. If you only have an iPad then you could use online TurboTax. But that License code does not work for online TT.
Please see the TurboTax FAQ below for troubleshooting installation:
If you are running into specific errors or any other information that may help us assist you further, please reach out to us.