If you switched from an iOS device to a new iOS device, than this
help page might help.
If you switched from an Android device to a new iOS device, than you have to make a new purchase.
Android and iOS are different companies with different policies, procedures, and in this case, even a different version of the game. One can't swap purchases between Apple and Android. That's not just an EK thing, that's an industry thing that has little room for independent developers to complain.