Swords & Some Magic
Due to some delay while processing the request to the App Store, the purchase confirmation window may appear with the delay (5-10 seconds). You have to wait a bit. Also, this window will not appear if you don't have the Internet connection.
Besides that, the window may not appear at all, even if you have the Internet connection. In that case you have to restart the game (see the "How to turn off the game correctly?" question in the Support section), then try to make the purchase again.